diff --git a/.changeset/9126-pack-dynamic-head-report.md b/.changeset/9126-pack-dynamic-head-report.md
new file mode 100644
index 0000000000..069f52b46b
--- /dev/null
+++ b/.changeset/9126-pack-dynamic-head-report.md
@@ -0,0 +1,4 @@
+---
+---
+
+Report-only, `scripts/`-only: `check-i18n-dead-keys.mjs`'s pack half now prints every dynamic template head it applied, how many `en` leaves fall under each, and how many of those that head alone keeps out of the candidate list. No verdict, tier or candidate changes — the sibling designer corpus already reports the same reading, and this closes the asymmetry without adopting its threshold (objectui#9126).
diff --git a/scripts/__tests__/check-i18n-dead-keys.test.ts b/scripts/__tests__/check-i18n-dead-keys.test.ts
index 0e365cb862..57ad04d184 100644
--- a/scripts/__tests__/check-i18n-dead-keys.test.ts
+++ b/scripts/__tests__/check-i18n-dead-keys.test.ts
@@ -1806,3 +1806,146 @@ describe('the text sweep does not descend into `.objectui-tmp` (objectui#9201)',
     expect(String(thrown?.stderr ?? '')).toContain('No such file or directory');
   });
 });
+
+/**
+ * objectui#9126 — the pack half applies every collected dynamic head unfiltered
+ * and, until this leg, said NOTHING about which heads those were or how far
+ * each reached. The whole deliverable is that reading: `sweep()` now returns
+ * one row per applied head, and the CLI prints them.
+ *
+ * ⛔ The card's fences are what these tests are for, and the sharpest one is
+ * NEGATIVE: reporting must not become filtering. Every test below that measures
+ * a row is paired with one measuring that the candidate list did not move —
+ * a row is a description of a subtraction that already happened, never a new
+ * one. The threshold question (`MIN_HEAD_SEGMENTS`, which the DESIGNER half
+ * applies to its own corpus) is deliberately not answered here; it is a
+ * maintainer's call and no test here may smuggle one in.
+ */
+describe('the applied dynamic heads are REPORTED, not filtered (objectui#9126)', () => {
+  /** A pack with one family under a head that names a top-level namespace and
+   *  nothing else, and one under a head that names a segment of its own. */
+  const HEAD_REPORT_EN = `const en = {
+  wideNs: { alpha: 'A', beta: 'B', gamma: 'C' },
+  narrowNs: { group: { one: 'One', two: 'Two' } },
+} as const;
+export default en;
+`;
+
+  /** Builds a key under each head from a runtime value, and ALSO asks for one
+   *  leaf under the wide head by its literal name — so `leavesUnder` and
+   *  `heldLive` are different numbers for that row and the difference has a
+   *  cause a reader can point at. */
+  const HEAD_REPORT_CONSUMER = `
+import { useObjectTranslation } from '${I18N_PKG}';
+export function Widget({ id }: { id: string }) {
+  const { t } = useObjectTranslation();
+  return [t('wideNs.alpha'), t(\`wideNs.\${id}\`), t(\`narrowNs.group.\${id}\`)];
+}
+`;
+
+  function headReportRoot() {
+    return repoWith({
+      'packages/i18n/src/locales/en.ts': HEAD_REPORT_EN,
+      'packages/x/src/Widget.tsx': HEAD_REPORT_CONSUMER,
+    });
+  }
+
+  const rowFor = (root: string, head: string) => sweep(root).appliedHeads.find((row) => row.head === head);
+
+  it('reports every head it applied, including one naming only a top-level namespace', () => {
+    const heads = sweep(headReportRoot()).appliedHeads.map((row) => row.head);
+    expect(heads.sort()).toEqual(['narrowNs.group.', 'wideNs.']);
+  });
+
+  it('counts the head’s own segments, so a namespace-wide head is visible AS one', () => {
+    const root = headReportRoot();
+    // The reading the card asks for: `wideNs.` names a top-level namespace and
+    // no more. Reported as `1` — and still applied, which the next test pins.
+    expect(rowFor(root, 'wideNs.')?.ownSegments).toBe(1);
+    expect(rowFor(root, 'narrowNs.group.')?.ownSegments).toBe(2);
+  });
+
+  it('⛔ NEGATIVE CONTROL: the namespace-wide head is still APPLIED — no key under it is a candidate', () => {
+    // The fence, as a test. If a future edit turns `ownSegments` into a filter,
+    // the three `wideNs.*` leaves become candidates and this goes red.
+    const { confirmed, needsReview, candidateCount } = sweep(headReportRoot());
+    expect(candidateCount).toBe(0);
+    expect(confirmed).toEqual([]);
+    expect(needsReview).toEqual([]);
+  });
+
+  it('counts every leaf UNDER the head, whether or not another leg already holds it', () => {
+    const root = headReportRoot();
+    expect(rowFor(root, 'wideNs.')?.leavesUnder).toBe(3);
+    expect(rowFor(root, 'narrowNs.group.')?.leavesUnder).toBe(2);
+  });
+
+  it('counts as HELD only the leaves no other leg keeps live', () => {
+    // `wideNs.alpha` has a literal call site, so the head is not what takes it
+    // out of the candidate list. Reporting it as held would overstate the
+    // head's reach — the same overstatement in the opposite direction to the
+    // silence this leg closes.
+    const root = headReportRoot();
+    expect(rowFor(root, 'wideNs.')?.heldLive).toBe(2);
+    expect(rowFor(root, 'narrowNs.group.')?.heldLive).toBe(2);
+  });
+
+  it('marks where each head came from', () => {
+    const root = headReportRoot();
+    expect(rowFor(root, 'wideNs.')?.via).toBe('direct');
+    expect(rowFor(root, 'narrowNs.group.')?.via).toBe('direct');
+  });
+
+  describe('measured on THIS repository', () => {
+    const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '../..');
+    const result = sweep(repoRoot);
+
+    it('reports one row per head the sweep actually applied — no head goes unreported', () => {
+      const gate = analyze(repoRoot);
+      const indirect = collectIndirectTemplateHeads(repoRoot, collectEnKeys(repoRoot));
+      const applied = new Set([...gate.dynamicHeads, ...indirect.heads.keys()]);
+      expect(applied.size, 'no heads at all — the whole cross-check would be vacuous').toBeGreaterThan(0);
+      expect(result.appliedHeads.map((row) => row.head).sort()).toEqual([...applied].sort());
+    });
+
+    it('every reported row describes a REAL subtraction — no key it counts is still a candidate', () => {
+      // The report must be a reading of the candidate list, not a parallel
+      // claim about it. A row whose keys were still candidates would be worse
+      // than the silence it replaces.
+      const candidates = new Set([...result.confirmed, ...result.needsReview.map((entry) => entry.key)]);
+      const leaves = [...collectEnKeys(repoRoot).leaves];
+      for (const row of result.appliedHeads) {
+        const under = leaves.filter((key) => key.startsWith(row.head));
+        expect(under.length, `${row.head} holds no leaves — its row would be vacuous`).toBe(row.leavesUnder);
+        expect(under.filter((key) => candidates.has(key)), `${row.head} reaches a key still in a tier`).toEqual([]);
+      }
+    });
+
+    it('⛔ the reading does not move the candidate list — heads stay unfiltered at EVERY depth', () => {
+      // The card's lit control, at repository scale. The pack half applies each
+      // collected head whatever its depth; the report says so and changes
+      // nothing. `heldLive` summing to the keys held out of the tiers is the
+      // arithmetic a reviewer can redo from the printed table.
+      const leaves = [...collectEnKeys(repoRoot).leaves];
+      const heldByAHead = leaves.filter((key) => result.appliedHeads.some((row) => key.startsWith(row.head)));
+      const candidates = new Set([...result.confirmed, ...result.needsReview.map((entry) => entry.key)]);
+      expect(heldByAHead.some((key) => candidates.has(key))).toBe(false);
+      expect(result.candidateCount).toBe(result.confirmed.length + result.needsReview.length);
+    });
+
+    it('⛔ does NOT adopt the designer half’s threshold for the packs', () => {
+      // objectui#9126 fences the threshold off as a maintainer's call. A head
+      // with no segment of its own is REPORTED here and REFUSED on the designer
+      // corpus; if the packs ever start refusing one too, that is a deliberate
+      // decision and this test is where it gets re-argued.
+      const rootOnly = result.appliedHeads.filter((row) => row.ownSegments < 2);
+      expect(rootOnly.length, 'no namespace-wide head on the tree — the pin has nothing to hold').toBeGreaterThan(0);
+      const leaves = [...collectEnKeys(repoRoot).leaves];
+      const candidates = new Set([...result.confirmed, ...result.needsReview.map((entry) => entry.key)]);
+      for (const row of rootOnly) {
+        const under = leaves.filter((key) => key.startsWith(row.head));
+        expect(under.filter((key) => candidates.has(key)), `${row.head} was filtered, not merely reported`).toEqual([]);
+      }
+    });
+  });
+});
diff --git a/scripts/check-i18n-dead-keys.mjs b/scripts/check-i18n-dead-keys.mjs
index 30e30037c7..dd6a9de783 100644
--- a/scripts/check-i18n-dead-keys.mjs
+++ b/scripts/check-i18n-dead-keys.mjs
@@ -1590,6 +1590,9 @@ export function collectIndirectTemplateHeads(root, packKeys = collectEnKeys(root
  *   needsReview: Array<{ key: string, hits: string[] }>,
  *   byNamespace: Map<string, { confirmed: string[], needsReview: string[] }>,
  *   indirectTemplateHeads: ReturnType<typeof collectIndirectTemplateHeads>,
+ *   appliedHeads: Array<{
+ *     head: string, ownSegments: number, leavesUnder: number, heldLive: number, via: string,
+ *   }>,
  * }}
  */
 export function sweep(root) {
@@ -1619,6 +1622,46 @@ export function sweep(root) {
     })
     .sort();
 
+  // objectui#9126 — what the head leg above ACTUALLY applied, as a reading.
+  //
+  // REPORT ONLY, and the ORDER of these two statements is the whole guarantee:
+  // `candidates` is already computed, from `heads` unfiltered, exactly as
+  // before. Nothing below feeds back into it — this block only measures a
+  // subtraction that was already made, so the candidate list is byte-identical
+  // with and without it. That is deliberate and fenced: the sibling corpus
+  // below DOES refuse a head with no segment of its own (`MIN_HEAD_SEGMENTS`),
+  // and whether the packs should adopt a threshold of their own is a
+  // maintainer's call this script does not make. What it can do without any
+  // threshold decision is stop being SILENT about it — a reader who sees only
+  // the candidate count has no way to learn how many keys were never offered,
+  // nor that a handful of heads account for nearly all of them.
+  //
+  // `ownSegments` is that reading, not a filter: the head minus its trailing
+  // dot, counted in segments, so a head naming ONLY a top-level namespace
+  // (`someNamespace.` -> 1) is visible as such in the report while still being
+  // applied in full.
+  //
+  // `heldLive` is the designer half's `headHeldCounts` definition, mirrored: of
+  // the leaves under this head, how many NO OTHER leg here already holds — i.e.
+  // exactly the keys this head alone keeps out of `candidates`. Heads do not
+  // nest today, but if two ever did, a leaf under both counts in both rows;
+  // the sibling counts the same way, and a per-head row that quietly dropped
+  // shared keys would under-report the same way this block exists to fix.
+  const appliedHeads = heads
+    .map((head) => {
+      const under = [...leaves].filter((key) => key.startsWith(head));
+      return {
+        head,
+        ownSegments: head.replace(/\.$/, '').split('.').length,
+        leavesUnder: under.length,
+        heldLive: under.filter(
+          (key) => !referencedKeys.has(key) && !branchPrefixes.some((prefix) => key.startsWith(prefix)),
+        ).length,
+        via: dynamicHeads.has(head) ? (indirect.heads.has(head) ? 'direct+indirect' : 'direct') : 'indirect',
+      };
+    })
+    .sort((a, b) => b.leavesUnder - a.leavesUnder || a.head.localeCompare(b.head));
+
   const footprints = textFootprint(root, candidates);
   const confirmed = candidates.filter((key) => footprints.get(key).length === 0);
   const needsReview = candidates
@@ -1645,6 +1688,7 @@ export function sweep(root) {
     needsReview,
     byNamespace,
     indirectTemplateHeads: indirect,
+    appliedHeads,
   };
 }
 
@@ -2118,6 +2162,9 @@ if (invokedDirectly) {
           candidateCount: result.candidateCount,
           confirmed: result.confirmed,
           needsReview: result.needsReview,
+          // objectui#9126 — every head the pack half applied, and what each
+          // holds. Reporting only: `candidateCount` above is unchanged by it.
+          appliedDynamicHeads: result.appliedHeads,
           indirectTemplateHeads: {
             counters: result.indirectTemplateHeads.counters,
             heads: Object.fromEntries(
@@ -2219,6 +2266,54 @@ if (invokedDirectly) {
       }
     }
 
+    // ── the dynamic heads this half APPLIED (objectui#9126) ─────────────────
+    // Every head the candidate list above was computed against, printed
+    // because until now it was not: this half applies each collected head
+    // unfiltered, so a key is held live by merely starting with one, and the
+    // report said nothing at all about which heads those were or how much each
+    // reached. The counts read as a candidate list that is simply short.
+    //
+    // ⛔ This block changes no verdict. The sibling corpus below REFUSES a head
+    // with no segment of its own; whether the packs want a threshold of their
+    // own is a maintainer's call and is deliberately not made here. Reporting
+    // needs no such decision — it only turns the silence into a reading.
+    {
+      const rows = result.appliedHeads;
+      const totalUnder = rows.reduce((sum, row) => sum + row.leavesUnder, 0);
+      const totalHeld = rows.reduce((sum, row) => sum + row.heldLive, 0);
+      const rootOnly = rows.filter((row) => row.ownSegments < 2);
+      const rootOnlyUnder = rootOnly.reduce((sum, row) => sum + row.leavesUnder, 0);
+      const rootOnlyHeld = rootOnly.reduce((sum, row) => sum + row.heldLive, 0);
+      console.log(
+        `\n${'='.repeat(78)}\ndynamic template heads APPLIED to the pack corpus — all ${rows.length}, ` +
+          'none filtered' +
+          `\n\n"under" is every en leaf sharing the head. "held" is how many of those NO other leg here ` +
+          `already keeps live — i.e. exactly the keys this head alone takes out of the candidate list, ` +
+          `so ${result.candidateCount} candidate(s) is a reading of the pack MINUS ${totalHeld} key(s) ` +
+          `across ${rows.length} head(s) (${totalUnder} leaves fall under a head in total; the ` +
+          'difference is leaves a literal call site holds anyway). "own" is how many segments the head ' +
+          'names beyond nothing: 1 means it names a top-level namespace and no more. Each head comes ' +
+          'from a real call site building a key from a runtime value — the row measures its REACH, and ' +
+          'says nothing about whether the head is right:',
+      );
+      console.log(`\n  ${'head'.padEnd(40)} ${'own'.padStart(3)} ${'under'.padStart(5)} ${'held'.padStart(5)}   via`);
+      for (const row of rows) {
+        console.log(
+          `  ${row.head.padEnd(40)} ${String(row.ownSegments).padStart(3)} ` +
+            `${String(row.leavesUnder).padStart(5)} ${String(row.heldLive).padStart(5)}   ${row.via}`,
+        );
+      }
+      if (rootOnly.length > 0) {
+        console.log(
+          `\n  ⚠️ ${rootOnly.length} of those head(s) name a top-level namespace and nothing else ` +
+            `(${rootOnly.map((row) => row.head).join(', ')}), together reaching ${rootOnlyUnder} leaf/leaves ` +
+            `and holding ${rootOnlyHeld} key(s) out of the candidate list on their own. That is the class ` +
+            'the designer half below refuses outright and this half applies in full. Both are reported; ' +
+            'only one is a decision, and it is not this one.',
+        );
+      }
+    }
+
     // ── the one-hop indirect template leg (objectui#8754) ───────────────────
     // Printed for the same reason the property-read rows above are: the leg
     // subtracts keys from the candidate set, so the tiers are shorter than they