diff --git a/.github/workflows/github-pages.yml b/.github/workflows/github-pages.yml
index 1a27cebcb..7511497ca 100644
--- a/.github/workflows/github-pages.yml
+++ b/.github/workflows/github-pages.yml
@@ -32,8 +32,11 @@ jobs:
           MKDOCS_EDIT_URI: edit/${{ github.ref_name }}/docs/
         run: |
           pip install mkdocs-material
+          node test/test_firmware_picker.js
+          node test/test_partition_catalog_viewer.js
           python scripts/sync_bootloader_manifest.py
           mkdocs build
+          cmp firmware/esp32_partition_catalog.json site/_data/esp32_partition_catalog.json
 
       - name: Deploy to GitHub Pages
         uses: peaceiris/actions-gh-pages@v4.1.0
diff --git a/docs/_javascript/esp32_partition_catalog.js b/docs/_javascript/esp32_partition_catalog.js
new file mode 100644
index 000000000..7901daf8a
--- /dev/null
+++ b/docs/_javascript/esp32_partition_catalog.js
@@ -0,0 +1,169 @@
+(function (global) {
+  "use strict";
+
+  function validateCatalog(catalog) {
+    if (!catalog || catalog.schema !== 1 || !Array.isArray(catalog.repositories) ||
+        !Array.isArray(catalog.releases) || !Array.isArray(catalog.builds) ||
+        !Array.isArray(catalog.unresolved) || !catalog.layouts ||
+        typeof catalog.layouts !== "object" || Array.isArray(catalog.layouts)) {
+      throw new Error("Unsupported partition catalog format");
+    }
+    return catalog;
+  }
+
+  function snapshot(catalog) {
+    return {
+      schema: catalog.schema,
+      generatedAt: catalog.generatedAt,
+      repositories: catalog.repositories,
+      counts: {
+        releases: catalog.releases.length,
+        builds: catalog.builds.length,
+        layouts: Object.keys(catalog.layouts).length,
+        unresolved: catalog.unresolved.length,
+      },
+    };
+  }
+
+  function jsonView(catalog, view) {
+    validateCatalog(catalog);
+    if (view === "all") return JSON.stringify(catalog, null, 2);
+    const result = snapshot(catalog);
+    if (view === "layouts") result.layouts = catalog.layouts;
+    else if (view === "releases") result.releases = catalog.releases;
+    else throw new Error("Unknown catalog view");
+    return JSON.stringify(result, null, 2);
+  }
+
+  function boardMinimums(catalog) {
+    validateCatalog(catalog);
+    const boards = new Map();
+    catalog.builds.forEach(function (build) {
+      const key = build.board.toLowerCase();
+      if (!boards.has(key)) {
+        boards.set(key, {
+          board: build.board, smallestBytes: null,
+          hasDualOta: false, hasNonDualOta: false, hasUnknownLayout: false,
+        });
+      }
+      const row = boards.get(key);
+      const layout = Object.prototype.hasOwnProperty.call(catalog.layouts, build.layout)
+        ? catalog.layouts[build.layout] : null;
+      if (!layout || !Array.isArray(layout.partitions)) {
+        row.hasUnknownLayout = true;
+        return;
+      }
+      const apps = layout.partitions.filter(function (entry) {
+        return Array.isArray(entry) && entry[0] === 0 &&
+          Number.isSafeInteger(entry[3]) && entry[3] > 0;
+      });
+      if (!apps.length) {
+        row.hasUnknownLayout = true;
+        return;
+      }
+      const smallest = Math.min.apply(null, apps.map((entry) => entry[3]));
+      row.smallestBytes = row.smallestBytes === null
+        ? smallest : Math.min(row.smallestBytes, smallest);
+      if (layout.dualOta === true) row.hasDualOta = true;
+      else if (layout.dualOta === false) row.hasNonDualOta = true;
+      else row.hasUnknownLayout = true;
+    });
+    return Array.from(boards.values()).sort(function (left, right) {
+      return left.board.localeCompare(right.board, "en", { sensitivity: "base" });
+    });
+  }
+
+  function formatSize(bytes) {
+    return bytes === null ? "Unknown" : (bytes / 1048576).toLocaleString(
+      "en-US", { maximumFractionDigits: 4 }
+    ) + " MiB";
+  }
+
+  function otaLayouts(row) {
+    if (row.hasUnknownLayout) return "Unknown layouts present";
+    if (row.hasDualOta && row.hasNonDualOta) return "Mixed (some lack dual OTA)";
+    return row.hasDualOta ? "Dual-slot OTA" : "No dual-slot OTA";
+  }
+
+  async function initializeViewer() {
+    const root = document.getElementById("partition-catalog");
+    if (!root || root.dataset.initialized) return;
+    root.dataset.initialized = "true";
+    const selector = document.getElementById("partition-catalog-view");
+    const status = document.getElementById("partition-catalog-status");
+    const code = document.getElementById("partition-catalog-json");
+    const link = document.getElementById("partition-catalog-open");
+    const raw = document.getElementById("partition-catalog-raw");
+    const search = document.getElementById("partition-catalog-search");
+    const tbody = document.getElementById("partition-catalog-boards");
+    const count = document.getElementById("partition-catalog-count");
+    try {
+      const response = await global.fetch(link.href, { cache: "no-cache" });
+      if (!response.ok) throw new Error("HTTP " + response.status);
+      const catalog = validateCatalog(await response.json());
+      const render = function () {
+        // Catalog text is data, never HTML. Only format the large builds array
+        // when the reader explicitly requests the complete catalog.
+        code.textContent = jsonView(catalog, selector.value);
+      };
+      raw.addEventListener("toggle", function () { if (raw.open) render(); });
+      if (raw.open) render();
+      selector.disabled = false;
+      selector.addEventListener("change", render);
+      const rows = boardMinimums(catalog).map(function (board) {
+        const tr = document.createElement("tr");
+        const name = document.createElement("th");
+        name.scope = "row";
+        name.textContent = board.board;
+        const size = document.createElement("td");
+        size.textContent = formatSize(board.smallestBytes);
+        if (board.smallestBytes !== null) {
+          const bytes = document.createElement("small");
+          bytes.textContent = board.smallestBytes.toLocaleString("en-US") + " bytes";
+          size.appendChild(bytes);
+        }
+        const layout = document.createElement("td");
+        layout.textContent = otaLayouts(board);
+        tr.appendChild(name);
+        tr.appendChild(size);
+        tr.appendChild(layout);
+        tbody.appendChild(tr);
+        return { name: board.board.toLowerCase(), element: tr };
+      });
+      const filter = function () {
+        const query = search.value.trim().toLowerCase();
+        let visible = 0;
+        rows.forEach(function (row) {
+          row.element.hidden = !row.name.includes(query);
+          if (!row.element.hidden) visible++;
+        });
+        count.textContent = "Showing " + visible + " of " + rows.length + " boards.";
+      };
+      filter();
+      search.disabled = false;
+      search.addEventListener("input", filter);
+      document.getElementById("partition-catalog-table").hidden = false;
+      const counts = snapshot(catalog).counts;
+      status.textContent = "Snapshot " + catalog.generatedAt + ": " +
+        counts.builds.toLocaleString("en-US") + " builds, " +
+        counts.releases.toLocaleString("en-US") + " releases, " +
+        counts.layouts + " layouts, " + counts.unresolved + " unresolved assets.";
+    } catch (error) {
+      status.textContent = "Could not load the catalog: " + error.message +
+        ". Use Open JSON or Download JSON to access the file directly.";
+      code.textContent = "Catalog preview unavailable.";
+    }
+  }
+
+  const api = Object.freeze({
+    validateCatalog, jsonView, boardMinimums, formatSize, otaLayouts, initializeViewer,
+  });
+  if (typeof module === "object" && module.exports) module.exports = api;
+  if (typeof document !== "undefined") {
+    if (document.readyState === "loading") {
+      document.addEventListener("DOMContentLoaded", initializeViewer, { once: true });
+    } else {
+      initializeViewer();
+    }
+  }
+})(typeof globalThis !== "undefined" ? globalThis : this);
diff --git a/docs/_javascript/firmware_picker.js b/docs/_javascript/firmware_picker.js
index 04263bfa7..44d5f13ca 100644
--- a/docs/_javascript/firmware_picker.js
+++ b/docs/_javascript/firmware_picker.js
@@ -1079,6 +1079,49 @@
     });
   }
 
+  // Count compiled builds, not files: merged and app-only downloads can belong
+  // to the same build, but still require different installation instructions.
+  function selectionProgress(profiles, filters) {
+    const count = (profiles || []).filter(function (profile) {
+      return profileMatchesFacets(profile, filters);
+    }).length;
+    return {
+      count: count,
+      state: count === 1 ? "single" : count ? "multiple" : "empty",
+      title: count === 1 ? "1 firmware build left" : count ? count + " firmware builds remain"
+        : "No matching firmware builds",
+      note: count === 1
+        ? filters && filters.install ? "Confirm your board and install choice."
+          : "Choose an install operation."
+        : count ? "Choose options to narrow the results."
+          : "Change or clear choices to see available builds.",
+    };
+  }
+
+  function choicesUseSameFirmware(profiles, filters, field, options) {
+    // Never equate install operations, even when they belong to one build.
+    if (!["hardware", "role", "logging", "mode", "firmwareProfile"].includes(field)) {
+      return false;
+    }
+    const ignored = field === "firmwareProfile" ? PROFILE_FIELDS : field;
+    const compatible = (profiles || []).filter(function (profile) {
+      return profileMatchesFacets(profile, filters, ignored);
+    });
+    const choices = (options || []).filter(function (option) { return option.value; });
+    if (!compatible.length || !choices.length) return false;
+    // Ignore the current choice before comparing alternatives. Having one
+    // result now does not imply that another button would keep the same build.
+    return choices.every(function (option) {
+      const choice = field === "firmwareProfile" ? firmwareProfileFilters(option.value)
+        : { [field]: option.value };
+      if (!choice) return false;
+      const selection = Object.assign({}, filters, choice);
+      return compatible.every(function (profile) {
+        return profileMatchesFacets(profile, selection);
+      });
+    });
+  }
+
   function selectionUrl(url, filters, automaticChipFamily) {
     const result = new URL(url);
     FACET_FIELDS.forEach(function (field) {
@@ -1751,6 +1794,8 @@
     const shareLink = root.querySelector('[data-role="share-link"]');
     const copyLinkButton = root.querySelector('[data-action="copy-link"]');
     const linkStatus = root.querySelector('[data-role="link-status"]');
+    const feedback = root.querySelector('[data-role="filter-feedback"]');
+    const resultLink = root.querySelector('[data-role="view-results"]');
     const controls = {};
     FACET_FIELDS.forEach(function (field) {
       controls[field] = form.querySelector('[data-field="' + field + '"]');
@@ -1762,6 +1807,10 @@
     const filters = {};
     let automaticChipFamily = false;
     const groupPrefix = "firmware-picker-" + (++pickerInstanceCount);
+    if (resultLink) {
+      result.id = result.id || groupPrefix + "-results";
+      resultLink.href = "#" + result.id;
+    }
 
     function updateSelectionUrl() {
       const url = selectionUrl(global.location.href, filters, automaticChipFamily);
@@ -1855,6 +1904,35 @@
       renderRadioChoices(container, options, selected, groupPrefix + "-" + field, field);
       const fieldset = container.closest("fieldset");
       if (fieldset) fieldset.disabled = values.length === 0;
+      setRefinementHint(container, field, options);
+    }
+
+    function setRefinementHint(container, field, options) {
+      const fieldset = container.closest("fieldset");
+      if (!fieldset) return;
+      let badge = fieldset.querySelector('[data-role="same-firmware"]');
+      let hint = fieldset.querySelector('[data-role="refinement-hint"]');
+      if (!badge) {
+        badge = createElement("span", "Same firmware");
+        badge.className = "firmware-picker-same-firmware";
+        badge.dataset.role = "same-firmware";
+        fieldset.querySelector("legend").appendChild(badge);
+        hint = createElement("p");
+        hint.className = "firmware-picker-control-help firmware-picker-refinement-hint";
+        hint.dataset.role = "refinement-hint";
+        hint.id = groupPrefix + "-" + field + "-hint";
+        fieldset.insertBefore(hint, container);
+      }
+      const same = choicesUseSameFirmware(catalog.profiles, filters, field, options);
+      badge.hidden = !same;
+      hint.hidden = !same;
+      hint.textContent = same ? "These choices do not narrow the firmware builds." +
+        (["logging", "mode"].includes(field) ? " They can change setup instructions." : "") : "";
+      const describedBy = (fieldset.getAttribute("aria-describedby") || "")
+        .split(/\s+/).filter(function (id) { return id && id !== hint.id; });
+      if (same) describedBy.push(hint.id);
+      if (describedBy.length) fieldset.setAttribute("aria-describedby", describedBy.join(" "));
+      else fieldset.removeAttribute("aria-describedby");
     }
 
     function setControlOptions(field, values) {
@@ -1931,6 +2009,7 @@
       renderRadioChoices(profileControl, [{ value: "", label: "Any" }].concat(profileChoices),
         firmwareProfileValue(filters), groupPrefix + "-firmwareProfile", "firmwareProfile");
       profileControl.closest("fieldset").disabled = profileChoices.length === 0;
+      setRefinementHint(profileControl, "firmwareProfile", profileChoices);
       const hardwareVariants = valuesForField("hardware");
       const hardwareVariantControl = root.querySelector(
         '[data-role="hardware-variant-control"]'
@@ -1963,9 +2042,20 @@
         return field !== "chipFamily" && !filters[field];
       });
       const matches = matchingProfiles();
+      if (feedback) {
+        const progress = selectionProgress(catalog.profiles, filters);
+        feedback.hidden = false;
+        feedback.dataset.state = progress.state;
+        feedback.querySelector('[data-role="filter-count"]').textContent = progress.title;
+        feedback.querySelector('[data-role="filter-note"]').textContent = progress.note;
+      }
+      if (resultLink) resultLink.hidden = true;
 
       if (missingFields.length) {
-        if (missingFields.length === CHOICE_FIELDS.length - 1 && !filters.chipFamily) {
+        if (matches.length === 1) {
+          status.textContent = "One firmware build remains. Confirm the hardware and install operation. " +
+            "Choices marked 'Same firmware' do not narrow the result further.";
+        } else if (missingFields.length === CHOICE_FIELDS.length - 1 && !filters.chipFamily) {
           status.textContent = "Pick options in any order. " +
             matches.length + " compatible configurations are available.";
         } else {
@@ -1993,6 +2083,7 @@
               );
             });
             result.hidden = false;
+            if (resultLink) resultLink.hidden = false;
           }
         }
         return;
@@ -2024,6 +2115,7 @@
         );
       });
       result.hidden = false;
+      if (resultLink) resultLink.hidden = false;
     }
 
     function renderBootloader() {
@@ -2265,6 +2357,8 @@
     firmwareProfileFilters: firmwareProfileFilters,
     firmwareProfileLabel: firmwareProfileLabel,
     firmwareProfileChoices: firmwareProfileChoices,
+    selectionProgress: selectionProgress,
+    choicesUseSameFirmware: choicesUseSameFirmware,
     selectionUrl: selectionUrl,
     selectionFromUrl: selectionFromUrl,
     canonicalAsset: canonicalAsset,
diff --git a/docs/_stylesheets/esp32_partition_catalog.css b/docs/_stylesheets/esp32_partition_catalog.css
new file mode 100644
index 000000000..2147ef91c
--- /dev/null
+++ b/docs/_stylesheets/esp32_partition_catalog.css
@@ -0,0 +1,101 @@
+.partition-catalog {
+  min-width: 0;
+  margin: 1rem 0;
+}
+
+.partition-catalog-controls {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 0.6rem 1rem;
+}
+
+.partition-catalog-controls label {
+  font-weight: 700;
+}
+
+.partition-catalog-controls select,
+.partition-catalog-controls input {
+  max-width: 100%;
+  padding: 0.5rem;
+  border: 1px solid var(--md-default-fg-color--light);
+  border-radius: 0.25rem;
+  background: var(--md-default-bg-color);
+  color: var(--md-default-fg-color);
+  font: inherit;
+}
+
+.partition-catalog-controls select:focus-visible,
+.partition-catalog-controls input:focus-visible,
+.partition-catalog-table:focus-visible,
+.partition-catalog-json:focus-visible {
+  outline: 2px solid var(--md-accent-fg-color);
+  outline-offset: 2px;
+}
+
+.partition-catalog-table {
+  max-height: 32rem;
+  overflow: auto;
+  overscroll-behavior: contain;
+}
+
+.partition-catalog [hidden] {
+  display: none !important;
+}
+
+.md-typeset .partition-catalog-table table {
+  display: table;
+  width: 100%;
+  margin: 0;
+}
+
+.partition-catalog-table thead th {
+  position: sticky;
+  top: 0;
+  background: var(--md-default-bg-color);
+}
+
+.partition-catalog-table tbody th {
+  overflow-wrap: anywhere;
+}
+
+.partition-catalog-table td small {
+  display: block;
+  color: var(--md-default-fg-color--light);
+  white-space: nowrap;
+}
+
+.partition-catalog-raw {
+  margin-top: 1rem;
+}
+
+.partition-catalog-raw summary {
+  cursor: pointer;
+}
+
+.partition-catalog-raw .partition-catalog-controls {
+  margin-top: 1rem;
+}
+
+@media (max-width: 600px) {
+  .md-typeset .partition-catalog-table table th,
+  .md-typeset .partition-catalog-table table td {
+    padding: 0.5rem;
+  }
+}
+
+.md-typeset .partition-catalog-json {
+  max-height: 32rem;
+  overflow: auto;
+  overscroll-behavior: contain;
+  border: 1px solid var(--md-default-fg-color--lightest);
+  border-radius: 0.25rem;
+}
+
+.md-typeset .partition-catalog-json > code {
+  display: block;
+  padding: 1rem;
+  white-space: pre;
+  overflow-wrap: normal;
+  word-break: normal;
+}
diff --git a/docs/_stylesheets/firmware_picker.css b/docs/_stylesheets/firmware_picker.css
index a23f3421e..4ab0e86ed 100644
--- a/docs/_stylesheets/firmware_picker.css
+++ b/docs/_stylesheets/firmware_picker.css
@@ -38,6 +38,46 @@
   margin: 1.2rem 0;
 }
 
+.firmware-picker [hidden] {
+  display: none !important;
+}
+
+.firmware-picker-feedback {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 0.6rem;
+  padding: 0.65rem 0.8rem;
+  border: 1px solid var(--picker-border);
+  border-left: 0.3rem solid var(--picker-accent);
+  border-radius: 0.4rem;
+  background: var(--md-default-bg-color, white);
+}
+
+.firmware-picker-feedback[data-state="single"] {
+  border-color: var(--picker-accent);
+}
+
+.firmware-picker-feedback p {
+  margin: 0.2rem 0 0;
+  font-size: 0.75rem;
+  line-height: 1.35;
+}
+
+.firmware-picker-feedback a {
+  flex-shrink: 0;
+  padding: 0.55rem 0.65rem;
+  border: 1px solid var(--picker-accent);
+  border-radius: 0.35rem;
+  font-size: 0.8rem;
+  font-weight: 700;
+}
+
+.firmware-picker-feedback a:focus-visible {
+  outline: 0.16rem solid var(--picker-accent);
+  outline-offset: 0.12rem;
+}
+
 .firmware-picker-order-note {
   margin: 1rem 0 0;
   color: var(--md-default-fg-color--light);
@@ -76,10 +116,26 @@
 }
 
 .firmware-picker-radio-control > legend {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
   margin-bottom: 0.35rem;
   padding: 0;
 }
 
+.firmware-picker-same-firmware {
+  padding: 0.15rem 0.45rem;
+  border: 1px solid var(--picker-border);
+  border-radius: 999px;
+  font-size: 0.65rem;
+  font-weight: 600;
+  background: color-mix(in srgb, var(--picker-accent) 10%, transparent);
+}
+
+.firmware-picker-refinement-hint {
+  font-size: 0.75rem;
+}
+
 .firmware-picker-select-control select,
 .firmware-asset-browser input {
   width: 100%;
@@ -190,6 +246,7 @@
 
 .firmware-picker-result {
   border-top: 0.3rem solid var(--picker-accent);
+  scroll-margin-top: 4rem;
 }
 
 .firmware-picker-eyebrow {
@@ -309,6 +366,17 @@
     grid-template-columns: 1fr;
   }
 
+  .firmware-picker-feedback {
+    position: sticky;
+    top: 0.5rem;
+    z-index: 2;
+    box-shadow: 0 0.2rem 0.5rem rgb(0 0 0 / 10%);
+  }
+
+  .md-typeset .firmware-picker-feedback {
+    top: calc(var(--md-header-height, 2.4rem) + 0.4rem);
+  }
+
   .firmware-picker-facts {
     grid-template-columns: 1fr;
   }
diff --git a/docs/cli_commands.md b/docs/cli_commands.md
index 228dc58a4..58a32ac75 100644
--- a/docs/cli_commands.md
+++ b/docs/cli_commands.md
@@ -914,7 +914,18 @@ All display-equipped Companion builds show the screen at boot in the default
 selected profile's timeout (15 seconds by default); button input restarts that
 timer. This also applies to previously saved button modes. Saved `off` and
 pairing-only modes still suppress the boot screen. Repeaters, room servers,
-and sensors do not gain this Companion-only boot wake.
+and sensors do not gain this Companion-only normal-UI boot wake.
+
+On display-equipped Companions, repeaters, room servers, and sensors, a small
+`Starting...` screen appears as soon as the board, primary filesystem, and
+display are initialized, before radio initialization and serial-settle delays.
+If a new identity is needed, it changes to `Generating key` with an animated
+spinner during radio entropy collection. OLED/TFT updates are paced at 150 ms;
+e-paper uses a slower one-second cadence. Saved `off` and pairing-only modes
+still suppress this startup screen. The normal UI's boot timeout starts only
+when that UI is ready, so key generation does not consume it. Filesystem
+recovery and the display driver's own initialization can still delay the first
+visible frame; the firmware cannot draw before those operations finish.
 
 Startup shows `Loading identity` while reading a saved identity. `Generating key`
 and its spinner are used only when creating a replacement/new identity;
diff --git a/docs/esp32_partition_catalog.md b/docs/esp32_partition_catalog.md
index 25966d6ed..08dc41ef3 100644
--- a/docs/esp32_partition_catalog.md
+++ b/docs/esp32_partition_catalog.md
@@ -5,6 +5,46 @@ The canonical LUT is `firmware/esp32_partition_catalog.json` in this fork.
 assets. MeshCore Open bundles an identical copy for offline phone updates.
 There is no need to run a command on the phone or download old firmware there.
 
+## Smallest partition by board
+
+The table shows each board's **smallest known application partition** across
+all cataloged releases, roles, and profiles. It does not count smaller NVS or
+filesystem partitions. Sizes use MiB (1,048,576 bytes), with exact bytes below.
+Mixed layouts means some releases have dual-slot OTA and others do not.
+These are historical factory-image minimums, not measurements of your device;
+use `get storage.layout` to check its actual installed layout.
+
+<div class="partition-catalog" id="partition-catalog">
+  <div class="partition-catalog-controls">
+    <label for="partition-catalog-search">Board</label>
+    <input id="partition-catalog-search" type="search" placeholder="Search board name" autocomplete="off" disabled>
+    <a id="partition-catalog-open" href="../_data/esp32_partition_catalog.json">Open JSON</a>
+    <a href="../_data/esp32_partition_catalog.json" download="esp32_partition_catalog.json">Download JSON</a>
+  </div>
+  <p id="partition-catalog-status" role="status" aria-live="polite">Loading catalog JSON...</p>
+  <p id="partition-catalog-count" role="status" aria-live="polite"></p>
+  <div class="partition-catalog-table" id="partition-catalog-table" tabindex="0" aria-label="Smallest application partition by board" hidden>
+    <table>
+      <thead><tr><th scope="col">Board</th><th scope="col">Smallest app partition</th><th scope="col">OTA layouts</th></tr></thead>
+      <tbody id="partition-catalog-boards"></tbody>
+    </table>
+  </div>
+  <details class="partition-catalog-raw" id="partition-catalog-raw">
+    <summary>Show JSON details</summary>
+    <div class="partition-catalog-controls">
+      <label for="partition-catalog-view">JSON view</label>
+      <select id="partition-catalog-view" disabled>
+        <option value="layouts">Snapshot and partition layouts</option>
+        <option value="releases">Release inventory</option>
+        <option value="all">Complete catalog (large)</option>
+      </select>
+    </div>
+    <pre class="partition-catalog-json" tabindex="0" aria-label="Partition catalog JSON"><code id="partition-catalog-json">Expand this section to view the JSON.</code></pre>
+  </details>
+</div>
+
+With JavaScript disabled, use [the complete JSON file](_data/esp32_partition_catalog.json).
+
 ## Coverage
 
 The initial snapshot enumerates every published release (including prereleases,
diff --git a/docs/firmware_picker.md b/docs/firmware_picker.md
index 471680dae..41ea381cb 100644
--- a/docs/firmware_picker.md
+++ b/docs/firmware_picker.md
@@ -8,8 +8,11 @@ MQTT and GPS show their app/WebConfig steps instead. See
 The [USB web console](https://flasher.meshcore.io/console) works with the
 default ASCII terminal on USB Companion and infrastructure roles.
 
-Pick the choices in any order. Every selection narrows all the other controls
-to firmware combinations that were actually built in the current release set.
+Pick the choices in any order. The controls stay limited to compatible
+firmware combinations that were actually built in the current release set.
+The result count stays visible while you scroll through the filters on a phone.
+**Same firmware** marks choices that do not narrow the builds any further;
+they remain usable because they can change the setup instructions.
 The optional chip-family filter (ESP32, nRF52, RP2040, or STM32) can narrow the
 hardware list first. You can skip it: picking hardware fills it in automatically.
 Chip family and hardware are the only dropdowns. All remaining choices use
@@ -51,6 +54,14 @@ from the published firmware assets.
   </p>
 
   <form class="firmware-picker-form" data-role="form">
+    <div class="firmware-picker-feedback firmware-picker-wide" data-role="filter-feedback" hidden>
+      <div aria-live="polite" aria-atomic="true">
+        <strong data-role="filter-count"></strong>
+        <p data-role="filter-note"></p>
+      </div>
+      <a data-role="view-results" hidden>View files</a>
+    </div>
+
     <details class="firmware-picker-chip-family firmware-picker-wide">
       <summary data-role="chip-family-summary">Optional: chip family</summary>
       <p id="firmware-picker-chip-help">Skip this if you know your board. Picking hardware selects its chip family automatically. Choose Any to clear this filter.</p>
diff --git a/docs/lora_ota_automation.md b/docs/lora_ota_automation.md
index 9c0bb18fd..954180e7b 100644
--- a/docs/lora_ota_automation.md
+++ b/docs/lora_ota_automation.md
@@ -774,6 +774,20 @@ verbose device log contains its `COUNT` acknowledgement; an immediate device
 `ERR` or a missing acknowledgement fails during startup instead of surfacing
 later as a catalog timeout.
 
+Newer `motatool` builds prepare raw-DEFLATE blocks with Zopfli before opening
+the source link. This host-only work has a separate 30-minute preparation
+limit (`--seeder-prepare-wait SECONDS`) and reports progress while waiting.
+The five-second device acknowledgement timer (`--seeder-start-wait SECONDS`)
+starts after the final `compressed N/N blocks` message, not when compression
+starts. Neither compression progress nor a host "serving" message proves
+device readiness: the runner still requires the device's `COUNT` reply.
+Older motatool builds without a preparation phase keep the original device
+startup timeout. Process exits and device errors still fail immediately.
+Preparation happens after TempRadio is armed, so leave enough lease time for
+both compression and transfer, especially on a slow host. The suggested
+TempRadio budget includes the preparation limit; it remains a warning, not a
+hard requirement to select that entire worst-case budget.
+
 ```bash
 ./tools/lora_ota/lora_ota.sh ./release.mota "Remote Target" \
   --controller-serial /dev/ttyACM0 \
@@ -905,7 +919,8 @@ the destination.
    target, far-to-near relays, and source. A separate controller is moved and
    read back through Binary; a shared Full Companion instead schedules its
    bounded local override while Binary remains the transport. The runner
-   rejects a TempRadio window that cannot cover setup, seeder startup,
+   rejects TempRadio windows under 20 minutes and warns when the selected
+   window does not cover worst-case setup, seeder preparation and startup,
    discovery, the transfer timeout, final polling, and install checks.
 7. Start `motatool serve`, discover the exact eight-hex manifest ID, request
    `ota pull <id> flash`, and poll until that same ID reports ready. A seeder
diff --git a/docs/test-results/heltec_v3_preview3_ram.md b/docs/test-results/heltec_v3_preview3_ram.md
new file mode 100644
index 000000000..caf3fa0ef
--- /dev/null
+++ b/docs/test-results/heltec_v3_preview3_ram.md
@@ -0,0 +1,92 @@
+# Full Companion RAM audit and Heltec V3 preview 3
+
+Date: 2026-10-02. Baseline: `0ccac453` plus the early startup-screen changes
+included in this revision. All 13 selected ordinary Full builds passed the
+existing linked runtime RAM guard. This is a targeted audit, not a claim that
+every Companion has been rebuilt or hardware-qualified.
+
+## Builds needing the most attention
+
+| Hardware | Available bytes | Reserved bytes | Margin bytes |
+| --- | ---: | ---: | ---: |
+| Generic ESP-NOW | 143,872 | 142,336 | 1,536 |
+| Tracker V2 (FEM on) | 180,000 | 177,746 | 2,254 |
+| Heltec V3 | 185,032 | 182,016 | 3,016 |
+| XIAO ESP32-C3 | 146,048 | 142,336 | 3,712 |
+| Heltec CT62 | 146,240 | 142,336 | 3,904 |
+| Wireless Tracker | 184,304 | 178,946 | 5,358 |
+| Heltec T096 (FEM on) | 84,152 | 75,298 | 8,854 |
+| Heltec T1 | 84,488 | 75,298 | 9,190 |
+| LilyGo TLora V2.1.1.6 | 185,304 | 173,840 | 11,464 |
+| Heltec V2 | 187,176 | 173,840 | 13,336 |
+| TBeam SX1276 | 194,160 | 169,744 | 24,416 |
+| TBeam SX1262 | 196,112 | 169,744 | 26,368 |
+| Heltec T114 | 84,336 | 46,880 | 37,456 |
+
+The six smallest margins belong to non-PSRAM ESP32 Full Companions. They pass
+their existing release capacities but have little room for further growth.
+Heltec T096 and T1 are the next constrained screen-equipped nRF52 Full builds.
+T114 Full passes; the failed older T114 BLE-only recipe is not a Full failure.
+
+Values come from the firmware RAM guard in the retained local
+`out/companion-ram-*-before.log` build logs. Available bytes exclude statically
+reserved memory and unavailable internal regions; the reservation covers
+startup allocations and a transient allowance. The margin is not measured
+live free heap or a prediction of time to failure. No safety budget was lowered.
+
+## V3 solution under test
+
+The opt-in `platformio.heltec-v3-preview3.ini` profile uses the existing
+NimBLE-Arduino adapter, pinned to version 2.5.1, instead of Bluedroid. It retains
+the current ordinary V3 Full capacities: 100 contacts, 40 channels, and 256
+offline frames, including during mOTA. It adds no new queue-sharing or storage
+changes and does not enable the larger 350-contact capacity trial.
+
+| V3 image | Available internal bytes | Reserved bytes | Margin bytes |
+| --- | ---: | ---: | ---: |
+| Published preview 2 | 185,040 | 182,016 | 3,024 |
+| Preview 3 | 200,152 | 182,016 | 18,136 |
+
+Compared with published preview 2, preview 3 recovers 15,112 bytes of internal
+RAM without removing Full features. Its bootloader and partition-table bytes
+match preview 2. The normal release matrix is unchanged.
+
+Bluetooth still provides the Companion server, encrypted PIN pairing,
+bonding, MAC policy and stealth controls. Existing Bluedroid bonds are not
+migrated: forget the old device in the phone's Bluetooth settings and pair
+again after installation. This does not require erasing contacts or identity.
+
+The preview also contains the early `Starting...` screen and animated key
+generation display. The saved Off and pairing-only display modes remain
+respected. Normal UI timeout starts after startup. Fresh installs still
+default to Bluetooth on and infrastructure WiFi off; saved WiFi-on settings
+remain on. Use `set wifi.enabled 1` to enable WiFi.
+
+## Verification and remaining work
+
+The real embedded build passes the unchanged RAM guard and fits both existing
+WiFi OTA slots. Capability checks inspect the linked ELF, packaged application
+and WebConfig gzip asset. The package includes ELF-bound RAM proof and hashes.
+
+Adapter regressions exercise actual NimBLE transport code under sanitizers,
+including identity/bond failures, encrypted PIN authentication, stealth,
+notifications, MTU gating and frame retry. Startup-screen, display policy,
+Companion preferences, USB defaults, identity and frame-queue regressions are
+also checked. Embedded compilation uses the actual pinned NimBLE library.
+
+This is still a hardware-test preview. V3 first-boot screen, phone pairing and
+reconnection, contact sync, WiFi/BLE coexistence, mOTA sending, and sustained
+load need physical verification. A build passing RAM checks does not establish
+that all reported V3 boot symptoms are fixed. Do not make this stack the default
+on every board before those checks.
+
+Reproduce with one PlatformIO process at a time:
+
+```sh
+pio run -c platformio.heltec-v3-preview3.ini \
+  -e Heltec_v3_companion_radio_full_preview3 -t mergebin
+python3 -B test/test_heltec_v3_preview_profile.py
+python3 -B test/test_nimble_companion.py
+python3 -B test/test_startup_screen.py
+python3 -B test/test_firmware_ram.py
+```
diff --git a/mkdocs.yml b/mkdocs.yml
index 796a1eb6f..75df14432 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -6,6 +6,9 @@ repo_name: !ENV [MKDOCS_REPO_NAME, 'meshcore-dev/meshcore']
 repo_url: !ENV [MKDOCS_REPO_URL, 'https://github.com/meshcore-dev/meshcore/']
 edit_uri: !ENV [MKDOCS_EDIT_URI, 'edit/main/docs/']
 
+hooks:
+  - scripts/docs_partition_catalog.py
+
 # Keep historical URLs for bookmarks while showing only the organized copies.
 not_in_nav: |
   /*_validation.md
@@ -110,17 +113,19 @@ extra_css:
   - _stylesheets/notification_builder.css
   - https://unpkg.com/leaflet@1.9.4/dist/leaflet.css
   - _stylesheets/extra.css
-  - _stylesheets/firmware_picker.css?v=20260929-1
+  - _stylesheets/firmware_picker.css?v=20261001-feedback-1
   - _stylesheets/telemetry_decoder.css
   - _stylesheets/management_decoder.css
   - _stylesheets/filter_tool.css
   - _stylesheets/preset_test.css?v=20260923-2
+  - _stylesheets/esp32_partition_catalog.css?v=20261001-1
 
 extra_javascript:
   - _javascript/notification_builder.js?v=20260930-audio-start
   - https://unpkg.com/leaflet@1.9.4/dist/leaflet.js
-  - _javascript/firmware_picker.js?v=20260929-4
+  - _javascript/firmware_picker.js?v=20261001-feedback-1
   - _javascript/telemetry_decoder.js
   - _javascript/management_decoder.js
   - _javascript/filter_tool.js?v=20261002-hashbytes-2plus
   - _javascript/preset_test.js?v=20260923-2
+  - _javascript/esp32_partition_catalog.js?v=20261001-1
diff --git a/platformio.heltec-v3-preview3.ini b/platformio.heltec-v3-preview3.ini
new file mode 100644
index 000000000..00a2097f6
--- /dev/null
+++ b/platformio.heltec-v3-preview3.ini
@@ -0,0 +1,81 @@
+; Heltec V3 Full Companion 1.17.1.8 preview3. See README.txt for source and pairing.
+[platformio]
+extra_configs =
+  platformio.ini
+  variants/*/platformio.ini
+
+[env:Heltec_v3_companion_radio_full_preview3]
+extends = env:Heltec_v3_companion_radio_full
+board_build.flash_mode = dio
+board_build.partitions = default_8MB.csv
+build_unflags =
+  -DMAX_CONTACTS=350
+  -DLORA_FREQ=869.618
+  -DLORA_SF=8
+  -DDISABLE_WIFI_OTA=1
+  -fexceptions
+build_flags =
+  ${env:Heltec_v3_companion_radio_full.build_flags}
+  -D MAX_CONTACTS=100
+  -D COMPANION_RADIO_FULL=1
+  -D ENABLE_USB_INTERFACE=1
+  -D BLE_PIN_CODE=123456
+  -D ENABLE_OTA=1
+  -UOTA_FLASH_STORE
+  -UOTA_SD_STORE
+  -UDISABLE_LORA_OTA
+  -UWEBCONFIG_DISABLED
+  -UDISABLE_WIFI_OTA
+  -D OTA_SEEDER_ONLY=1
+  -D MOTA_TARGET_ID=0
+  -D WIFI_OTA_SEEDER=1
+  -D COMPANION_FEATURE_TEMP_RADIO=1
+  -D COMPANION_FEATURE_OTA_CLI=1
+  -D COMPANION_FEATURE_USB_MOTA_SOURCE=1
+  -D COMPANION_FEATURE_NETWORK_TERMINAL=1
+  -D COMPANION_FEATURE_MEMORY_DIAGNOSTICS=1
+  -D MESHCORE_EXPANDED_PARTITION_PROFILE=1
+  -D LIGHTWEIGHT_WIFI_OTA=1
+  -D MESH_DEBUG=1
+  -D MESH_PACKET_LOGGING=1
+  -D MESH_USE_NIMBLE_ARDUINO=1
+  -D CONFIG_BT_NIMBLE_MAX_CONNECTIONS=1
+  -D CONFIG_BT_NIMBLE_ROLE_CENTRAL_DISABLED=1
+  -D CONFIG_BT_NIMBLE_ROLE_OBSERVER_DISABLED=1
+  -D LORA_FREQ=910.525
+  -D LORA_BW=62.5
+  -D LORA_SF=7
+  -D LORA_CR=5
+  -D MESHCORE_USA_RADIO_PRESET=1
+  -D CASCADE_PROFILE=1
+  -D DEFAULT_PATH_HASH_MODE=2
+  -D DEFAULT_LOOP_DETECT=1
+  -D DEFAULT_CAD_ENABLED=0
+  -D DEFAULT_RX_DELAY_BASE=2.0f
+  -D DEFAULT_AGC_RESET_INTERVAL_SECONDS=8
+  -D DEFAULT_ADVERT_INTERVAL_MINUTES=0
+  -D DEFAULT_FLOOD_ADVERT_INTERVAL_HOURS=83
+  -D DEFAULT_MULTI_ACKS=1
+  -D DEFAULT_MANUAL_ADD_CONTACTS=1
+  -D DEFAULT_AUTOADD_CONFIG=0
+  -D DEFAULT_POWERSAVING_ENABLED=1
+  -D DEFAULT_RXPS_ENABLED=1
+  -D DEFAULT_RXPS_LEVEL=8
+  -D DEFAULT_RXPS_PREAMBLE=16
+  -D RXPS_FIXED_ENABLED=1
+  -D RXPS_FIXED_LEVEL=8
+  -D RXPS_FIXED_PREAMBLE=16
+  -D DEFAULT_WIFI_POWER_SAVE_MODE=0
+  -D FIRMWARE_VERSION='"v1.17.1.8-preview3"'
+  -D FIRMWARE_BUILD_DATE='"02-Oct-2026"'
+  -D FIRMWARE_BUILD_EPOCH=1790928488
+  -D OTA_VARIANT='"Heltec_v3_companion_radio_full"'
+  -fno-exceptions
+build_src_filter =
+  ${env:Heltec_v3_companion_radio_full.build_src_filter}
+  +<helpers/ota/*.cpp>
+  +<helpers/ota/detools/detools.c>
+lib_deps =
+  ${env:Heltec_v3_companion_radio_full.lib_deps}
+  h2zero/NimBLE-Arduino @ 2.5.1
+lib_ignore = ESP32 BLE Arduino
diff --git a/scripts/docs_partition_catalog.py b/scripts/docs_partition_catalog.py
new file mode 100644
index 000000000..a1fa1b3fa
--- /dev/null
+++ b/scripts/docs_partition_catalog.py
@@ -0,0 +1,19 @@
+"""Publish the canonical partition catalog without keeping a second source copy."""
+
+from pathlib import Path
+
+from mkdocs.structure.files import File
+
+
+CATALOG_URI = "_data/esp32_partition_catalog.json"
+
+
+def on_files(files, config):
+    source = (
+        Path(config.config_file_path).resolve().parent
+        / "firmware" / "esp32_partition_catalog.json"
+    )
+    if not source.is_file():
+        raise FileNotFoundError(f"Canonical partition catalog is missing: {source}")
+    files.append(File.generated(config, CATALOG_URI, abs_src_path=str(source)))
+    return files
diff --git a/test/test_firmware_picker.js b/test/test_firmware_picker.js
index e9a85ab74..f23f6d94a 100644
--- a/test/test_firmware_picker.js
+++ b/test/test_firmware_picker.js
@@ -1513,3 +1513,74 @@ assert(!picker.firmwareProfileChoices(catalog.profiles, {
   hardware: 'Station_G2', role: 'repeater', variant: 'missing',
 }).some(item => item.filters.variant === 'missing'));
 console.log('combined firmware profile choices and legacy links passed');
+
+// Mobile progress counts builds, not the installation files for each build.
+const feedbackFilters = {hardware: 'Heltec_v3', role: 'companion'};
+const v3Feedback = controlled.profiles.find(p => p.target === 'Heltec_v3_companion_radio_full');
+const feedbackCatalog = [Object.assign({}, v3Feedback, {
+  installKinds: ['merged-bin', 'bin'],
+})];
+const feedbackSnapshot = JSON.stringify(feedbackCatalog);
+assert.deepStrictEqual(picker.selectionProgress(feedbackCatalog, feedbackFilters), {
+  count: 1, state: 'single', title: '1 firmware build left',
+  note: 'Choose an install operation.',
+});
+for (const install of ['merged-bin', 'bin']) {
+  const progress = picker.selectionProgress(feedbackCatalog, {...feedbackFilters, install});
+  assert.strictEqual(progress.count, 1);
+  assert(progress.note.includes('Confirm your board and install choice'));
+}
+assert.strictEqual(picker.selectionProgress(controlled.profiles, {}).state, 'multiple');
+assert.strictEqual(picker.selectionProgress(controlled.profiles, {}).count, controlled.profiles.length);
+assert.strictEqual(picker.selectionProgress(feedbackCatalog, {hardware: 'Missing'}).state, 'empty');
+assert.strictEqual(picker.selectionProgress([], {}).count, 0);
+assert.strictEqual(picker.selectionProgress([], {}).title, 'No matching firmware builds');
+assert.strictEqual(picker.selectionProgress(feedbackCatalog).count, 1);
+
+function feedbackOptions(values) {
+  return [{value: ''}].concat(values.map(value => ({value})));
+}
+assert(picker.choicesUseSameFirmware(feedbackCatalog, feedbackFilters, 'logging',
+  feedbackOptions(v3Feedback.loggingModes)));
+assert(picker.choicesUseSameFirmware(feedbackCatalog, {...feedbackFilters, logging: 'usb'}, 'logging',
+  feedbackOptions(v3Feedback.loggingModes)));
+assert(picker.choicesUseSameFirmware(feedbackCatalog, feedbackFilters, 'mode',
+  feedbackOptions(picker.profileFieldValues(v3Feedback, 'mode'))));
+assert(picker.choicesUseSameFirmware(feedbackCatalog, feedbackFilters, 'firmwareProfile',
+  picker.firmwareProfileChoices(feedbackCatalog, feedbackFilters)));
+// A sole available option can be marked without disabling it or selecting it.
+assert(picker.choicesUseSameFirmware(feedbackCatalog, feedbackFilters, 'role',
+  feedbackOptions(['companion'])));
+assert(!picker.choicesUseSameFirmware(feedbackCatalog, feedbackFilters, 'install',
+  feedbackOptions(['merged-bin', 'bin'])));
+
+// One currently selected build is not enough: alternatives may change builds.
+const feedbackAlternatives = [
+  {...feedbackCatalog[0], loggingModes: ['none', 'usb'], mode: 'usb', connectionModes: ['usb']},
+  {...feedbackCatalog[0], target: 'second-build', loggingModes: ['wifi'],
+    mode: 'wifi', connectionModes: ['wifi'], feature: 'standard', ota: 'none'},
+];
+const selectedFeedback = {...feedbackFilters, logging: 'usb'};
+assert.strictEqual(picker.selectionProgress(feedbackAlternatives, selectedFeedback).count, 1);
+assert(!picker.choicesUseSameFirmware(feedbackAlternatives, selectedFeedback, 'logging',
+  feedbackOptions(['none', 'usb', 'wifi'])));
+assert(!picker.choicesUseSameFirmware(feedbackAlternatives, {...feedbackFilters, mode: 'usb'}, 'mode',
+  feedbackOptions(['usb', 'wifi'])));
+const selectedProfileFeedback = {...feedbackFilters, feature: 'full', ota: 'lora-source', variant: 'default'};
+assert(!picker.choicesUseSameFirmware(feedbackAlternatives, selectedProfileFeedback, 'firmwareProfile',
+  picker.firmwareProfileChoices(feedbackAlternatives, selectedProfileFeedback)));
+// Multiple builds can all share a runtime choice; report that accurately too.
+assert(picker.choicesUseSameFirmware(feedbackAlternatives.map(p => ({...p, loggingModes: ['none', 'usb']})),
+  feedbackFilters, 'logging', feedbackOptions(['none', 'usb'])));
+for (const partial of [{feature: 'full'}, {ota: 'lora-source'}]) {
+  const selection = {...feedbackFilters, ...partial};
+  assert(picker.choicesUseSameFirmware(feedbackCatalog, selection, 'firmwareProfile',
+    picker.firmwareProfileChoices(feedbackCatalog, selection)));
+}
+assert(!picker.choicesUseSameFirmware(feedbackCatalog, feedbackFilters, 'firmwareProfile',
+  [{value: 'invalid'}]));
+assert(!picker.choicesUseSameFirmware(feedbackCatalog, feedbackFilters, 'role', [{value: ''}]));
+assert(!picker.choicesUseSameFirmware([], {}, 'role', feedbackOptions(['companion'])));
+assert.strictEqual(JSON.stringify(feedbackCatalog), feedbackSnapshot);
+assert.deepStrictEqual(feedbackFilters, {hardware: 'Heltec_v3', role: 'companion'});
+console.log('build counts, non-refining choices, install safety and partial-link feedback passed');
diff --git a/test/test_heltec_v3_preview_profile.py b/test/test_heltec_v3_preview_profile.py
new file mode 100644
index 000000000..15e6b5f11
--- /dev/null
+++ b/test/test_heltec_v3_preview_profile.py
@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""Keep the opt-in V3 preview Full, capacity-preserving, and reproducible."""
+
+import configparser
+from pathlib import Path
+import re
+import unittest
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+class HeltecV3PreviewProfileTest(unittest.TestCase):
+    def setUp(self):
+        self.config = configparser.ConfigParser(interpolation=None)
+        self.config.read(ROOT / "platformio.heltec-v3-preview3.ini")
+        self.env = self.config["env:Heltec_v3_companion_radio_full_preview3"]
+
+    def test_full_features_and_existing_capacities(self):
+        flags = self.env["build_flags"]
+        for name in (
+                "COMPANION_RADIO_FULL", "ENABLE_USB_INTERFACE", "ENABLE_OTA",
+                "OTA_SEEDER_ONLY", "WIFI_OTA_SEEDER",
+                "COMPANION_FEATURE_TEMP_RADIO", "COMPANION_FEATURE_OTA_CLI",
+                "COMPANION_FEATURE_USB_MOTA_SOURCE",
+                "COMPANION_FEATURE_NETWORK_TERMINAL",
+                "COMPANION_FEATURE_MEMORY_DIAGNOSTICS"):
+            self.assertIn("-D " + name + "=1", flags)
+        self.assertIn("-D BLE_PIN_CODE=123456", flags)
+        self.assertIn("-D MAX_CONTACTS=100", flags)
+        self.assertNotIn("-D MAX_GROUP_CHANNELS", flags)
+        self.assertNotIn("-D OFFLINE_QUEUE_SIZE", flags)
+        self.assertNotIn("-D OTA_SHARED_COMPANION_QUEUE", flags)
+        self.assertNotIn("-D ONE_KEY_DM_SHARED_OFFLINE_QUEUE", flags)
+        self.assertNotIn("-D MESH_MIN_RUNTIME_HEAP", flags)
+        self.assertEqual(self.env["extends"], "env:Heltec_v3_companion_radio_full")
+        self.assertIn("${env:Heltec_v3_companion_radio_full.build_flags}", flags)
+
+    def test_nimble_is_pinned_and_not_in_the_ordinary_release_matrix(self):
+        self.assertIn("-D MESH_USE_NIMBLE_ARDUINO=1", self.env["build_flags"])
+        self.assertIn("h2zero/NimBLE-Arduino @ 2.5.1", self.env["lib_deps"])
+        self.assertIn("${env:Heltec_v3_companion_radio_full.lib_deps}",
+                      self.env["lib_deps"])
+        self.assertEqual(self.env["lib_ignore"], "ESP32 BLE Arduino")
+        base = configparser.ConfigParser(interpolation=None, strict=False)
+        base.read(ROOT / "platformio.ini")
+        self.assertNotIn("platformio.heltec-v3-preview3.ini",
+                         base["platformio"]["extra_configs"])
+
+    def test_version_and_partition_contract(self):
+        self.assertEqual(self.env["board_build.flash_mode"], "dio")
+        self.assertEqual(self.env["board_build.partitions"], "default_8MB.csv")
+        self.assertIn("v1.17.1.8-preview3", self.env["build_flags"])
+        self.assertNotIn("DISABLE_LORA_OTA=1", self.env["build_flags"])
+        # Never set a flag that removes the WiFi/BLE/sensor/display features.
+        self.assertNotRegex(self.env["build_flags"], re.compile(
+            r"-D\s*(WEBCONFIG_DISABLED|DISABLE_WIFI_OTA|UI_NO_\w+|"
+            r"ENV_EXCLUDE_\w+)(?:=|\s|$)"))
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/test/test_partition_catalog_viewer.js b/test/test_partition_catalog_viewer.js
new file mode 100644
index 000000000..7bfdff462
--- /dev/null
+++ b/test/test_partition_catalog_viewer.js
@@ -0,0 +1,164 @@
+"use strict";
+
+const assert = require("assert");
+const viewer = require("../docs/_javascript/esp32_partition_catalog.js");
+const catalog = require("../firmware/esp32_partition_catalog.json");
+
+assert.strictEqual(viewer.validateCatalog(catalog), catalog);
+const layouts = JSON.parse(viewer.jsonView(catalog, "layouts"));
+assert.deepStrictEqual(layouts.layouts, catalog.layouts);
+assert.strictEqual(layouts.counts.builds, catalog.builds.length);
+assert.strictEqual(layouts.counts.releases, catalog.releases.length);
+assert.strictEqual(layouts.counts.unresolved, catalog.unresolved.length);
+assert.strictEqual(layouts.builds, undefined);
+assert.strictEqual(layouts.releases, undefined);
+assert(viewer.jsonView(catalog, "layouts").length < 50000);
+const releases = JSON.parse(viewer.jsonView(catalog, "releases"));
+assert.deepStrictEqual(releases.releases, catalog.releases);
+assert.strictEqual(releases.builds, undefined);
+assert.deepStrictEqual(JSON.parse(viewer.jsonView(catalog, "all")), catalog);
+assert.throws(() => viewer.jsonView(catalog, "unknown"), /Unknown catalog view/);
+assert.throws(() => viewer.validateCatalog({ schema: 2 }), /Unsupported/);
+assert.throws(() => viewer.validateCatalog(Object.assign({}, catalog, { layouts: [] })), /Unsupported/);
+
+const minimums = viewer.boardMinimums(catalog);
+assert.strictEqual(minimums.length, new Set(catalog.builds.map((build) => build.board.toLowerCase())).size);
+const v3 = minimums.find((row) => row.board.toLowerCase() === "heltec_v3");
+assert.strictEqual(v3.smallestBytes, 3342336);
+assert.strictEqual(viewer.formatSize(v3.smallestBytes), "3.1875 MiB");
+assert.strictEqual(viewer.otaLayouts(v3), "Dual-slot OTA");
+assert.strictEqual(viewer.formatSize(null), "Unknown");
+
+const sample = {
+  schema: 1, repositories: [], releases: [], unresolved: [],
+  layouts: {
+    large: { dualOta: true, partitions: [[1, 2, 0x9000, 4096, "nvs", 0],
+      [0, 16, 0x10000, 2097152, "app0", 0], [0, 17, 0x210000, 2097152, "app1", 0]] },
+    small: { dualOta: true, partitions: [[0, 16, 0x10000, 2097152, "app0", 0],
+      [0, 17, 0x210000, 1310720, "app1", 0]] },
+    single: { dualOta: false, slotBytes: null,
+      partitions: [[0, 0, 0x10000, 3145728, "factory", 0]] },
+    noApps: { dualOta: false, partitions: [[1, 2, 0x9000, 4096, "nvs", 0]] },
+  },
+  builds: [
+    { board: "Board_A", layout: "large" },
+    { board: "board_a", layout: "small" },
+    { board: "Board_B", layout: "single" },
+    { board: "Board_C", layout: "single" },
+    { board: "Board_C", layout: "large" },
+    { board: "Board_D", layout: "missing" },
+    { board: "Board_E", layout: "noApps" },
+    { board: "Board_F", layout: "large" },
+    { board: "Board_F", layout: "missing" },
+  ],
+};
+const expectedSample = JSON.stringify(sample);
+const sampleRows = viewer.boardMinimums(sample);
+assert.strictEqual(JSON.stringify(sample), expectedSample);
+assert.strictEqual(sampleRows.length, 6);
+assert.strictEqual(sampleRows[0].smallestBytes, 1310720); // Smaller inactive slot, not NVS.
+assert.strictEqual(sampleRows[1].smallestBytes, 3145728); // A single-app layout still has an app size.
+assert.strictEqual(viewer.otaLayouts(sampleRows[1]), "No dual-slot OTA");
+assert.strictEqual(viewer.otaLayouts(sampleRows[2]), "Mixed (some lack dual OTA)");
+assert.strictEqual(sampleRows[3].smallestBytes, null);
+assert.strictEqual(sampleRows[4].smallestBytes, null);
+assert.strictEqual(sampleRows[5].smallestBytes, 2097152);
+assert.strictEqual(viewer.otaLayouts(sampleRows[5]), "Unknown layouts present");
+
+function element() {
+  return {
+    dataset: {}, children: [], hidden: false, textContent: "",
+    addEventListener: function (event, handler) { this[event] = handler; },
+    appendChild: function (child) { this.children.push(child); child.parentElement = this; },
+  };
+}
+
+function fakePage() {
+  const elements = {
+    "partition-catalog": { dataset: {} },
+    "partition-catalog-view": {
+      value: "layouts", disabled: true,
+      addEventListener: function (event, handler) { this[event] = handler; },
+    },
+    "partition-catalog-status": { textContent: "Loading..." },
+    "partition-catalog-json": { textContent: "" },
+    "partition-catalog-open": {
+      href: "https://example.test/MeshCore/_data/esp32_partition_catalog.json",
+    },
+    "partition-catalog-raw": Object.assign(element(), { open: false }),
+    "partition-catalog-search": Object.assign(element(), { value: "", disabled: true }),
+    "partition-catalog-boards": element(),
+    "partition-catalog-count": element(),
+  };
+  elements.table = Object.assign(element(), { hidden: true });
+  elements["partition-catalog-table"] = elements.table;
+  global.document = { getElementById: (id) => elements[id], createElement: element };
+  return elements;
+}
+
+async function testBrowser() {
+  const oldFetch = global.fetch;
+  const oldDocument = global.document;
+  try {
+    let calls = 0;
+    global.fetch = async function (url) {
+      calls++;
+      assert.strictEqual(url, "https://example.test/MeshCore/_data/esp32_partition_catalog.json");
+      return { ok: true, json: async () => catalog };
+    };
+    const page = fakePage();
+    await viewer.initializeViewer();
+    assert.strictEqual(page["partition-catalog-view"].disabled, false);
+    assert.strictEqual(page["partition-catalog-json"].textContent, ""); // Details are lazy.
+    assert.strictEqual(page.table.hidden, false);
+    assert.strictEqual(page["partition-catalog-boards"].children.length, minimums.length);
+    assert.strictEqual(page["partition-catalog-search"].disabled, false);
+    page["partition-catalog-search"].value = "HELTEC_V3";
+    page["partition-catalog-search"].input();
+    assert.strictEqual(page["partition-catalog-count"].textContent, "Showing 1 of " + minimums.length + " boards.");
+    const visible = page["partition-catalog-boards"].children.filter((row) => !row.hidden);
+    assert.strictEqual(visible[0].children[0].textContent, v3.board);
+    assert.strictEqual(visible[0].children[1].textContent, "3.1875 MiB");
+    assert.strictEqual(visible[0].children[1].children[0].textContent, "3,342,336 bytes");
+    page["partition-catalog-search"].value = "no matching board";
+    page["partition-catalog-search"].input();
+    assert.strictEqual(page["partition-catalog-count"].textContent, "Showing 0 of " + minimums.length + " boards.");
+    page["partition-catalog-raw"].open = true;
+    page["partition-catalog-raw"].toggle();
+    assert.deepStrictEqual(JSON.parse(page["partition-catalog-json"].textContent).layouts, catalog.layouts);
+    assert(page["partition-catalog-status"].textContent.includes(
+      catalog.builds.length.toLocaleString("en-US") + " builds"));
+    page["partition-catalog-view"].value = "all";
+    page["partition-catalog-view"].change();
+    assert.deepStrictEqual(JSON.parse(page["partition-catalog-json"].textContent), catalog);
+    await viewer.initializeViewer();
+    assert.strictEqual(calls, 1);
+
+    global.fetch = async () => ({ ok: false, status: 404 });
+    const missing = fakePage();
+    await viewer.initializeViewer();
+    assert(missing["partition-catalog-status"].textContent.includes("HTTP 404"));
+    assert(missing["partition-catalog-status"].textContent.includes("Open JSON"));
+    assert.strictEqual(missing["partition-catalog-view"].disabled, true);
+    assert.strictEqual(missing.table.hidden, true);
+
+    global.fetch = async () => ({ ok: true, json: async () => ({ schema: 2 }) });
+    const invalid = fakePage();
+    await viewer.initializeViewer();
+    assert(invalid["partition-catalog-status"].textContent.includes("Unsupported"));
+
+    global.document = { getElementById: () => null };
+    global.fetch = async () => { throw new Error("Other pages must not fetch the catalog"); };
+    await viewer.initializeViewer();
+  } finally {
+    global.fetch = oldFetch;
+    global.document = oldDocument;
+  }
+}
+
+testBrowser().then(() => {
+  console.log("board minima, OTA warnings, search, JSON views, loading and error states passed");
+}).catch((error) => {
+  console.error(error);
+  process.exitCode = 1;
+});
diff --git a/tools/lora_ota/lora_ota.py b/tools/lora_ota/lora_ota.py
index a9d6ce4de..6da1acc75 100755
--- a/tools/lora_ota/lora_ota.py
+++ b/tools/lora_ota/lora_ota.py
@@ -136,6 +136,9 @@ POST_INSTALL_READY_PROBE_INTERVAL_SECONDS = 10
 # or build VM. Keep the explicit preparation workflow bounded; Pi-class radio
 # hosts should serve an already-built, hash-verified package instead.
 DEFAULT_PACKAGE_BUILD_TIMEOUT_SECONDS = 60 * 60
+# Newer motatool versions precompress every payload block before opening the
+# device link. CPU-bound preparation must not consume the COUNT attach timer.
+DEFAULT_SEEDER_PREPARE_WAIT_SECONDS = 30 * 60
 COMPANION_TERMINAL_START = "+++MESHCORE-TERM-START"
 COMPANION_TERMINAL_STOP = "+++MESHCORE-TERM-STOP"
 # Firmware may hold the apply reboot for up to 15 seconds while its reply
@@ -3040,6 +3043,7 @@ def recommended_temp_radio_minutes(
         remote_setup_seconds
         + source_setup_seconds
         + TEMP_RADIO_SWITCH_DELAY_SECONDS
+        + getattr(args, "seeder_prepare_wait", DEFAULT_SEEDER_PREPARE_WAIT_SECONDS)
         + args.seeder_start_wait
         + args.discovery_timeout
         + args.transfer_timeout_minutes * 60
@@ -3059,7 +3063,8 @@ def warn_short_temp_radio_window(
     if selected < recommended:
         print(
             f"warning: TempRadio window is {selected} minutes; {recommended} minutes "
-            "covers the combined worst-case setup, discovery, transfer, and "
+            "covers the combined worst-case setup, seeder preparation, discovery, "
+            "transfer, and "
             "final checks. Continuing; the lease may expire before OTA completes.",
             file=sys.stderr,
         )
@@ -3794,6 +3799,12 @@ def verify_shared_source_identity(
 
 class SeederProcess:
     READY_PATTERN = re.compile(r"(?mi)^\s*\[dev\]\s+COUNT\s*->\s*\d+\b")
+    PREPARE_PATTERN = re.compile(
+        r"(?mi)^[ \t]*preparing raw-DEFLATE transport\b.*\bbefore opening the link\b"
+    )
+    PREPARE_PROGRESS_PATTERN = re.compile(
+        r"(?mi)^[ \t]*compressed (\d+)/(\d+) blocks[ \t\r]*$"
+    )
     ATTACH_ERROR_PATTERN = re.compile(
         r"(?mi)^\s*\[dev\].*\b(?:ERR|ERROR)\b|"
         r"folder\s+(?:is\s+)?already\s+(?:owned|attached)|"
@@ -3856,7 +3867,16 @@ class SeederProcess:
             )
 
     def _wait_until_attached(self) -> None:
-        deadline = time.monotonic() + self.args.seeder_start_wait
+        started = time.monotonic()
+        attach_deadline = started + self.args.seeder_start_wait
+        prepare_wait = getattr(
+            self.args, "seeder_prepare_wait", DEFAULT_SEEDER_PREPARE_WAIT_SECONDS
+        )
+        prepare_deadline = started + prepare_wait
+        preparing = False
+        prepared = False
+        last_progress = None
+        next_notice = started + 30
         while True:
             self.ensure_running("during startup")
             detail = self._log_tail()
@@ -3867,11 +3887,57 @@ class SeederProcess:
                 )
             if self.READY_PATTERN.search(detail):
                 return
-            remaining = deadline - time.monotonic()
+            now = time.monotonic()
+            if not prepared:
+                progress = self.PREPARE_PROGRESS_PATTERN.findall(detail)
+                latest_progress = tuple(map(int, progress[-1])) if progress else None
+                if not preparing and (
+                    self.PREPARE_PATTERN.search(detail) or latest_progress is not None
+                ):
+                    preparing = True
+                    print(
+                        "[seeder] preparing compressed blocks on the host; "
+                        f"allowing up to {prepare_wait:g}s before the device "
+                        "COUNT timer starts"
+                    )
+                if preparing:
+                    if now >= prepare_deadline:
+                        raise OtaError(
+                            "motatool seeder host compression did not complete "
+                            f"within {prepare_wait:g}s; the device COUNT timer has "
+                            "not started. Increase --seeder-prepare-wait on a slow "
+                            "host and leave enough TempRadio time for the transfer.\n"
+                            f"{detail}"
+                        )
+                    if latest_progress is not None:
+                        done, total = latest_progress
+                        if done == total and total > 0:
+                            prepared = True
+                            preparing = False
+                            attach_deadline = now + self.args.seeder_start_wait
+                            print(
+                                "[seeder] host compression complete; "
+                                "waiting for the device COUNT acknowledgement"
+                            )
+                    if preparing and (
+                        latest_progress != last_progress or now >= next_notice
+                    ):
+                        counts = (
+                            f" ({latest_progress[0]}/{latest_progress[1]} blocks)"
+                            if latest_progress is not None else ""
+                        )
+                        print(
+                            f"[seeder] still compressing{counts}; "
+                            f"{now - started:.0f}s elapsed"
+                        )
+                        last_progress = latest_progress
+                        next_notice = now + 30
+            remaining = (prepare_deadline if preparing else attach_deadline) - now
             if remaining <= 0:
+                phase = " after host compression completed" if prepared else ""
                 raise OtaError(
                     "motatool seeder did not receive the device COUNT "
-                    f"acknowledgement within {self.args.seeder_start_wait:g}s:\n"
+                    f"acknowledgement within {self.args.seeder_start_wait:g}s{phase}:\n"
                     f"{detail}"
                 )
             time.sleep(min(0.1, remaining))
@@ -7889,7 +7955,14 @@ def build_parser() -> argparse.ArgumentParser:
     parser.add_argument("--discovery-interval", type=int, default=8)
     parser.add_argument("--poll-seconds", type=int, default=30)
     parser.add_argument("--transfer-timeout-minutes", type=int, default=110)
-    parser.add_argument("--seeder-start-wait", type=int, default=5)
+    parser.add_argument(
+        "--seeder-prepare-wait", type=int, default=DEFAULT_SEEDER_PREPARE_WAIT_SECONDS,
+        help="maximum seconds for motatool host compression before opening the device link",
+    )
+    parser.add_argument(
+        "--seeder-start-wait", type=int, default=5,
+        help="seconds to wait for the device COUNT acknowledgement after host compression",
+    )
     parser.add_argument(
         "--reboot-wait",
         type=int,
@@ -8124,8 +8197,8 @@ def validate_args(args: argparse.Namespace, parser: argparse.ArgumentParser) ->
             parser.error(f"{label} contains an unsupported control character")
     for name in (
         "reply_timeout", "discovery_timeout", "discovery_interval", "poll_seconds",
-        "transfer_timeout_minutes", "seeder_start_wait", "reboot_wait",
-        "package_build_timeout",
+        "transfer_timeout_minutes", "seeder_prepare_wait", "seeder_start_wait",
+        "reboot_wait", "package_build_timeout",
     ):
         if getattr(args, name) <= 0:
             parser.error(f"--{name.replace('_', '-')} must be positive")
diff --git a/tools/lora_ota/rak3401_mota_chain.py b/tools/lora_ota/rak3401_mota_chain.py
index ac63bee78..7f8b15430 100755
--- a/tools/lora_ota/rak3401_mota_chain.py
+++ b/tools/lora_ota/rak3401_mota_chain.py
@@ -2388,6 +2388,9 @@ def run_step(
         "--discovery-interval", str(args.discovery_interval),
         "--poll-seconds", str(args.poll_seconds),
         "--transfer-timeout-minutes", str(args.transfer_timeout_minutes),
+        "--seeder-prepare-wait", str(getattr(
+            args, "seeder_prepare_wait", ota.DEFAULT_SEEDER_PREPARE_WAIT_SECONDS
+        )),
         "--seeder-start-wait", str(args.seeder_start_wait),
         "--reboot-wait", str(args.reboot_wait),
         "--source-rxps-recovery-file",
@@ -2521,7 +2524,14 @@ def build_parser() -> argparse.ArgumentParser:
         help="seconds between transfer status checks; sparse checks leave airtime for OTA",
     )
     parser.add_argument("--transfer-timeout-minutes", type=int, default=90)
-    parser.add_argument("--seeder-start-wait", type=int, default=5)
+    parser.add_argument(
+        "--seeder-prepare-wait", type=int, default=ota.DEFAULT_SEEDER_PREPARE_WAIT_SECONDS,
+        help="maximum seconds for motatool host compression before opening the device link",
+    )
+    parser.add_argument(
+        "--seeder-start-wait", type=int, default=5,
+        help="seconds to wait for the device COUNT acknowledgement after host compression",
+    )
     parser.add_argument(
         "--reboot-wait",
         type=int,
@@ -2589,7 +2599,7 @@ def validate_args(args: argparse.Namespace, parser: argparse.ArgumentParser) ->
     for name in (
         "controller_baud", "source_baud", "reply_timeout", "discovery_timeout",
         "discovery_interval", "poll_seconds", "transfer_timeout_minutes",
-        "seeder_start_wait", "reboot_wait",
+        "seeder_prepare_wait", "seeder_start_wait", "reboot_wait",
     ):
         if getattr(args, name) <= 0:
             parser.error(f"--{name.replace('_', '-')} must be positive")
diff --git a/tools/lora_ota/test_lora_ota.py b/tools/lora_ota/test_lora_ota.py
index 77cccfb53..49698e15a 100644
--- a/tools/lora_ota/test_lora_ota.py
+++ b/tools/lora_ota/test_lora_ota.py
@@ -7446,6 +7446,7 @@ class Rak3401KnownUnsafeReleaseTests(unittest.TestCase):
             discovery_interval=8,
             poll_seconds=60,
             transfer_timeout_minutes=90,
+            seeder_prepare_wait=123,
             seeder_start_wait=5,
             reboot_wait=90,
             relay=[],
@@ -7477,6 +7478,7 @@ class Rak3401KnownUnsafeReleaseTests(unittest.TestCase):
                     )
                 command = nested.call_args.args[0]
                 self.assertEqual(command.count("--debug"), int(enabled))
+                self.assertEqual(command[command.index("--seeder-prepare-wait") + 1], "123")
                 self.assertEqual(command[command.index("--ota-hops") + 1], "3")
                 self.assertEqual(command[1], target_key)
                 self.assertEqual(command[command.index("--relay") + 1], f"{relay_key}=relay-password")
diff --git a/tools/lora_ota/test_lora_ota_seeder_startup.py b/tools/lora_ota/test_lora_ota_seeder_startup.py
new file mode 100644
index 000000000..4033b5043
--- /dev/null
+++ b/tools/lora_ota/test_lora_ota_seeder_startup.py
@@ -0,0 +1,290 @@
+"""Seeder startup timing tests; no radios or transmissions."""
+
+import argparse
+import contextlib
+import io
+from pathlib import Path
+import sys
+import tempfile
+import unittest
+from unittest import mock
+
+import lora_ota as ota
+import rak3401_mota_chain as rak_chain
+
+
+PREPARING = (
+    "motatool serve: 1 valid .mota in /served (recursive)\n"
+    "update.mota : blocks=264 size=541358\n"
+    "preparing raw-DEFLATE transport with Zopfli --i1000 before opening the link\n"
+)
+
+
+class Clock:
+    def __init__(self):
+        self.now = 0.0
+
+    def monotonic(self):
+        return self.now
+
+    def sleep(self, seconds):
+        # Advance quickly without waiting in real time. Deadline decisions
+        # remain based on the same clock used to select the visible log lines.
+        self.now += max(seconds, 1.0)
+
+
+class SeederStartupTests(unittest.TestCase):
+    def setUp(self):
+        self.args = argparse.Namespace(
+            motatool="motatool", source_serial="/dev/source",
+            source_tcp=None, source_baud=115200,
+            seeder_start_wait=5, seeder_prepare_wait=1800,
+        )
+        self.clock = Clock()
+        self.output = io.StringIO()
+        self.addCleanup(mock.patch.stopall)
+        mock.patch.object(ota.time, "monotonic", self.clock.monotonic).start()
+        mock.patch.object(ota.time, "sleep", self.clock.sleep).start()
+        self.redirect = contextlib.redirect_stdout(self.output)
+        self.redirect.__enter__()
+        self.addCleanup(self.redirect.__exit__, None, None, None)
+
+    def seeder(self, events):
+        seeder = ota.SeederProcess(self.args, Path("/served"), Path("/work"))
+        seeder.process = mock.Mock()
+        seeder.process.poll.return_value = None
+
+        def log_tail():
+            return next(
+                (text for when, text in reversed(events) if when <= self.clock.now),
+                "no seeder log output",
+            )
+
+        seeder._log_tail = mock.Mock(side_effect=log_tail)
+        return seeder
+
+    def test_slow_compression_gets_fresh_count_timer(self):
+        seeder = self.seeder([
+            (0, PREPARING),
+            (12, PREPARING + "  compressed 64/264 blocks\n"),
+            (30, PREPARING + "  compressed 256/264 blocks\n"),
+            (40, PREPARING + "  compressed 264/264 blocks\n"),
+            (44, "  compressed 264/264 blocks\n  [dev] COUNT -> 1\n"),
+        ])
+        seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 44)
+        self.assertIn("64/264 blocks", self.output.getvalue())
+        self.assertIn("host compression complete", self.output.getvalue())
+
+    def test_preparation_remains_recognized_after_header_leaves_log_tail(self):
+        seeder = self.seeder([
+            (0, PREPARING),
+            (10, "  compressed 64/264 blocks\n"),
+            (20, "  compressed 264/264 blocks\n"),
+            (24, "  [dev] COUNT -> 1\n"),
+        ])
+        seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 24)
+
+    def test_progress_can_identify_phase_without_header(self):
+        seeder = self.seeder([
+            (0, "  compressed 64/264 blocks\n"),
+            (20, "  compressed 264/264 blocks\n"),
+            (22, "  [dev] COUNT -> 1\n"),
+        ])
+        seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 22)
+
+    def test_crlf_progress_starts_count_timer(self):
+        seeder = self.seeder([
+            (0, PREPARING.replace("\n", "\r\n")),
+            (20, "  compressed 264/264 blocks\r\n"),
+        ])
+        with self.assertRaisesRegex(ota.OtaError, "after host compression completed"):
+            seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 25)
+
+    def test_invalid_completion_counts_do_not_start_count_timer(self):
+        self.args.seeder_prepare_wait = 10
+        for counts in ("0/0", "265/264"):
+            with self.subTest(counts=counts):
+                self.clock.now = 0
+                seeder = self.seeder([(0, PREPARING + f"  compressed {counts} blocks\n")])
+                with self.assertRaisesRegex(ota.OtaError, "host compression did not complete"):
+                    seeder._wait_until_attached()
+                self.assertEqual(self.clock.now, 10)
+
+    def test_final_progress_does_not_prove_device_readiness_or_reset_timer(self):
+        seeder = self.seeder([
+            (0, PREPARING),
+            (40, PREPARING + "  compressed 264/264 blocks\n"),
+        ])
+        with self.assertRaisesRegex(
+            ota.OtaError, "COUNT acknowledgement within 5s after host compression completed"
+        ):
+            seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 45)
+
+    def test_stalled_preparation_has_its_own_bounded_timeout(self):
+        self.args.seeder_prepare_wait = 60
+        seeder = self.seeder([(0, PREPARING)])
+        with self.assertRaisesRegex(ota.OtaError, "host compression did not complete within 60s"):
+            seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 60)
+        self.assertIn("still compressing", self.output.getvalue())
+        self.assertIn("30s elapsed", self.output.getvalue())
+
+    def test_progress_does_not_extend_preparation_deadline(self):
+        self.args.seeder_prepare_wait = 60
+        seeder = self.seeder([
+            (0, PREPARING),
+            (20, PREPARING + "  compressed 64/264 blocks\n"),
+            (40, PREPARING + "  compressed 128/264 blocks\n"),
+            (59, PREPARING + "  compressed 256/264 blocks\n"),
+        ])
+        with self.assertRaisesRegex(ota.OtaError, "host compression did not complete within 60s"):
+            seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 60)
+
+    def test_custom_preparation_timeout_is_honored(self):
+        self.args.seeder_prepare_wait = 12
+        seeder = self.seeder([(0, PREPARING)])
+        with self.assertRaisesRegex(ota.OtaError, "within 12s"):
+            seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 12)
+
+    def test_namespace_without_new_option_uses_default_preparation_limit(self):
+        del self.args.seeder_prepare_wait
+        seeder = self.seeder([(0, PREPARING)])
+        with self.assertRaisesRegex(ota.OtaError, "host compression did not complete within 1800s"):
+            seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, ota.DEFAULT_SEEDER_PREPARE_WAIT_SECONDS)
+
+    def test_device_error_stops_both_startup_phases_immediately(self):
+        for phase, elapsed in (("preparing", 10), ("attaching", 41)):
+            with self.subTest(phase=phase):
+                self.clock.now = 0
+                seeder = self.seeder([
+                    (0, PREPARING),
+                    (40, "  compressed 264/264 blocks\n"),
+                    (elapsed, "  [dev] ERR folder source unavailable\n"),
+                ])
+                with self.assertRaisesRegex(ota.OtaError, "rejected by the device"):
+                    seeder._wait_until_attached()
+                self.assertEqual(self.clock.now, elapsed)
+
+    def test_process_exit_stops_both_startup_phases_immediately(self):
+        for elapsed in (10, 41):
+            with self.subTest(elapsed=elapsed):
+                self.clock.now = 0
+                seeder = self.seeder([
+                    (0, PREPARING),
+                    (40, "  compressed 264/264 blocks\n"),
+                ])
+                seeder.process.poll.side_effect = lambda: 2 if self.clock.now >= elapsed else None
+                with self.assertRaisesRegex(ota.OtaError, "exited with status 2 during startup"):
+                    seeder._wait_until_attached()
+                self.assertEqual(self.clock.now, elapsed)
+
+    def test_legacy_tool_keeps_original_startup_timeout(self):
+        seeder = self.seeder([(0, "serving on /dev/source ... Ctrl-C to stop\n")])
+        with self.assertRaisesRegex(ota.OtaError, "COUNT acknowledgement within 5s:"):
+            seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 5)
+        self.assertNotIn("preparing compressed", self.output.getvalue())
+
+    def test_legacy_tool_is_ready_only_with_count(self):
+        seeder = self.seeder([
+            (0, "serving on /dev/source ... Ctrl-C to stop\n"),
+            (4, "  [dev] COUNT -> 1\n"),
+        ])
+        seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 4)
+
+    def test_genuine_count_can_confirm_readiness_without_final_progress(self):
+        seeder = self.seeder([
+            (0, PREPARING),
+            (10, PREPARING + "  [dev] COUNT -> 1\n"),
+        ])
+        seeder._wait_until_attached()
+        self.assertEqual(self.clock.now, 10)
+
+
+class SeederOptionTests(unittest.TestCase):
+    def arguments(self, chain=False, *options):
+        parser = rak_chain.build_parser() if chain else ota.build_parser()
+        values = [] if chain else ["release.mota", "remote"]
+        values.extend([
+            "--controller-serial", "/dev/controller",
+            "--source-serial", "/dev/source", *options,
+        ])
+        return parser, parser.parse_args(values)
+
+    def test_generic_and_chain_have_matching_defaults_and_overrides(self):
+        for chain in (False, True):
+            with self.subTest(chain=chain):
+                _, args = self.arguments(chain)
+                self.assertEqual(args.seeder_prepare_wait, 1800)
+                self.assertEqual(args.seeder_start_wait, 5)
+                _, args = self.arguments(chain, "--seeder-prepare-wait", "2400")
+                self.assertEqual(args.seeder_prepare_wait, 2400)
+
+    def test_both_runners_reject_nonpositive_preparation_timeouts(self):
+        for chain in (False, True):
+            for value in ("0", "-1"):
+                with self.subTest(chain=chain, value=value):
+                    parser, args = self.arguments(chain, "--seeder-prepare-wait", value)
+                    error = io.StringIO()
+                    validate = rak_chain.validate_args if chain else ota.validate_args
+                    with contextlib.redirect_stderr(error), self.assertRaises(SystemExit):
+                        validate(args, parser)
+                    self.assertIn("--seeder-prepare-wait must be positive", error.getvalue())
+
+    def test_preparation_budget_remains_advisory_with_twenty_minute_lease(self):
+        for chain in (False, True):
+            with self.subTest(chain=chain):
+                parser, args = self.arguments(chain, "--temp-radio-minutes", "20")
+                validate = rak_chain.validate_args if chain else ota.validate_args
+                with contextlib.redirect_stderr(io.StringIO()):
+                    validate(args, parser)
+                self.assertEqual(args.temp_values[-1], 20)
+                original = ota.recommended_temp_radio_minutes(args)
+                args.seeder_prepare_wait += 60
+                self.assertEqual(ota.recommended_temp_radio_minutes(args), original + 1)
+
+
+class SeederSubprocessTests(unittest.TestCase):
+    def test_real_subprocess_prepares_longer_than_attach_timeout(self):
+        # Exercise actual redirected output and lifecycle, not only mocked
+        # log snapshots. The child is a host-only stand-in, never motatool.
+        with tempfile.TemporaryDirectory() as directory:
+            args = argparse.Namespace(
+                motatool="unused", source_serial="/dev/unused",
+                source_tcp=None, source_baud=115200,
+                seeder_start_wait=1.0, seeder_prepare_wait=10,
+            )
+            seeder = ota.SeederProcess(args, Path(directory), Path(directory))
+            seeder.command = [
+                sys.executable, "-u", "-c",
+                "import time\n"
+                f"print({PREPARING!r}, flush=True)\n"
+                "time.sleep(1.25)\n"
+                "print('  compressed 264/264 blocks', flush=True)\n"
+                "time.sleep(0.2)\n"
+                "print('  [dev] COUNT -> 1', flush=True)\n"
+                "time.sleep(30)\n",
+            ]
+            output = io.StringIO()
+            with contextlib.redirect_stdout(output):
+                try:
+                    seeder.start()
+                    self.assertIsNone(seeder.process.poll())
+                finally:
+                    seeder.stop()
+            self.assertIn("running (device COUNT confirmed)", output.getvalue())
+            self.assertIn("host compression complete", output.getvalue())
+            self.assertIsNone(seeder.process)
+
+
+if __name__ == "__main__":
+    unittest.main()