diff --git a/.changeset/daring-deer-fly.md b/.changeset/daring-deer-fly.md
new file mode 100644
index 000000000..2ae88cf89
--- /dev/null
+++ b/.changeset/daring-deer-fly.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 4050
+---
+the STATE.md Quick Tasks log accepts milestone-suffixed section headings (Quick Tasks Completed (v1.1+)) — the exact-anchored lookup never matched them, so every /gsd:fast append and milestone reset silently failed before the columns were even checked; among several matching sections the one with a recognized table schema wins (#3860)
diff --git a/src/markdown-table.cts b/src/markdown-table.cts
index 0a532054d..a9fa61e6c 100644
--- a/src/markdown-table.cts
+++ b/src/markdown-table.cts
@@ -10,7 +10,8 @@
  * {ok,data|kind}; the two never mix (different modules).
  */
 
-import { collectSection, replaceSection } from './markdown-sectionizer.cjs';
+import { collectSection, collectSections, replaceSection } from './markdown-sectionizer.cjs';
+import type { HeadingToken, Section } from './markdown-sectionizer.cjs';
 import type { Result } from './write-set.cjs';
 export type { Result } from './write-set.cjs';
 
@@ -732,6 +733,57 @@ export function escapeCell(value: string): string {
  */
 export const QUICK_TASKS_SECTION_ABSENT = 'no Quick Tasks Completed section';
 
+/**
+ * #3860: heading predicate for STATE.md's Quick Tasks Completed section(s).
+ * The heading is a section LABEL, not data — milestone-scoped files
+ * legitimately carry suffixed headings (`### Quick Tasks Completed (v1.1+)`
+ * beside an archived `(v1.0)`), so the match is prefix-anchored with a word
+ * boundary, never exact: `Quick Tasks Completedness` must NOT match. Hoisted
+ * beside QUICK_TASKS_SECTION_ABSENT so `appendQuickTaskRow` and
+ * `resetQuickTaskRows` cannot drift apart again.
+ */
+const isQuickTasksHeading = (h: HeadingToken): boolean =>
+  /^quick tasks completed\b/i.test(h.text.trim());
+
+/**
+ * #3860: among ALL heading-matching sections, pick the first whose body is a
+ * table with a recognized Quick Tasks schema — a legacy/unparseable table
+ * first in document order no longer shadows a usable one further down. When
+ * NO section is usable, return the FIRST match so the caller's downstream
+ * error describes the real problem (unparseable/legacy table) instead of a
+ * false QUICK_TASKS_SECTION_ABSENT.
+ *
+ * Bounding: `collectSections` ends a candidate's body only at the NEXT
+ * matching heading — far too wide for splicing (it would swallow an
+ * intervening `## Deferred Items` table into the Quick Tasks body, and
+ * `appendQuickTaskRow`'s last-table-line scan would then splice the new row
+ * into that WRONG table). Each candidate is therefore re-collected through
+ * `collectSection` with an offset-precise predicate, whose default
+ * level-bounded stop (next heading of the same or higher level) is exactly
+ * the semantics the pre-#3860 single-section lookup had.
+ *
+ * Convention: "first" is document order — the newest-on-top layout the issue
+ * itself demonstrates (`(v1.1+)` above an archived `(v1.0)`). When several
+ * suffixed sections all carry recognized schemas, this layer has no signal
+ * for which milestone is active, so document order is the pinned tie-break.
+ */
+function selectQuickTasksSection(stateContent: string): Section | null {
+  const candidates = collectSections(stateContent, isQuickTasksHeading);
+  if (candidates.length === 0) return null;
+
+  const boundedOf = (cand: Section): Section | null =>
+    collectSection(stateContent, (h: HeadingToken) => h.offset === cand.heading.offset);
+
+  const firstBounded = boundedOf(candidates[0]);
+  for (const cand of candidates) {
+    const bounded = boundedOf(cand);
+    if (!bounded) continue;
+    const parsed = parseMarkdownTable(bounded.body);
+    if (parsed.ok && matchTableSchema(parsed.value.columns)?.id === 'QuickTasks') return bounded;
+  }
+  return firstBounded;
+}
+
 /** Fields needed to render one "Quick Tasks Completed" row (schema-driven). */
 export interface QuickTaskFields {
   description: string;
@@ -775,7 +827,7 @@ export function appendQuickTaskRow(
   stateContent: string,
   fields: QuickTaskFields,
 ): Result<{ content: string; row: string; variant: string }> {
-  const section = collectSection(stateContent, (h) => /^quick tasks completed$/i.test(h.text.trim()));
+  const section = selectQuickTasksSection(stateContent);
   if (!section) {
     return { ok: false, reason: QUICK_TASKS_SECTION_ABSENT };
   }
@@ -842,7 +894,7 @@ export function appendQuickTaskRow(
  * directories out from under the table (see `src/milestone.cts`'s
  * `archiveQuickTaskDirectories` / `cmdMilestoneComplete` wiring).
  *
- * Mirrors `appendQuickTaskRow`'s exact contract (same `collectSection` ->
+ * Mirrors `appendQuickTaskRow`'s exact contract (same `selectQuickTasksSection` ->
  * `parseMarkdownTable` -> `matchTableSchema` pipeline, same fail-loud posture,
  * same EOL-detect-before-split handling) rather than inventing a second one:
  *   - no "Quick Tasks Completed" heading -> `{ok:false, reason:
@@ -867,7 +919,7 @@ export function resetQuickTaskRows(
     return { ok: false, reason: 'empty or non-string input' };
   }
 
-  const section = collectSection(stateContent, (h) => /^quick tasks completed$/i.test(h.text.trim()));
+  const section = selectQuickTasksSection(stateContent);
   if (!section) {
     return { ok: false, reason: QUICK_TASKS_SECTION_ABSENT };
   }
diff --git a/tests/markdown-table.test.cjs b/tests/markdown-table.test.cjs
index 45ebea55d..496ea5a73 100644
--- a/tests/markdown-table.test.cjs
+++ b/tests/markdown-table.test.cjs
@@ -1136,6 +1136,215 @@ describe('TABLE_SCHEMAS parity: registry headers must appear verbatim in their s
   });
 });
 
+// ─── Quick Tasks heading tolerance (#3860) ────────────────────────────────────
+
+describe('Quick Tasks heading tolerance (#3860)', () => {
+  // Byte-identical table body to the bare-heading control — only the heading
+  // suffix differs, which is exactly the reporter's isolation.
+  const suffixedState = [
+    '# STATE',
+    '',
+    '### Quick Tasks Completed (v1.1+)',
+    '',
+    '| # | Description | Date | Commit | Directory |',
+    '|---|-------------|------|--------|-----------|',
+    '| 1 | fix typo | 2026-01-01 | abc1234 | — |',
+    '',
+    '### Blockers/Concerns',
+    'None',
+  ].join('\n');
+
+  const multiMilestoneState = [
+    '# STATE',
+    '',
+    '### Quick Tasks Completed (v1.1+)',
+    '',
+    '| # | Description | Date | Commit | Directory |',
+    '|---|-------------|------|--------|-----------|',
+    '| 250101-abc | first v1.1 task | 2025-01-01 | 0123abc | [dir](./quick/250101-abc/) |',
+    '',
+    '### Quick Tasks Completed (v1.0)',
+    '',
+    '| # | Description | Date | Commit | Directory |',
+    '|---|-------------|------|--------|-----------|',
+    '| 1 | legacy v1.0 task | 2024-06-01 | old1234 | — |',
+  ].join('\n');
+
+  // v1.0 first in document order with a LEGACY (unrecognized) schema — the
+  // usable v1.1+ table below it must not be shadowed (#3860 "worth deciding
+  // deliberately rather than inheriting from document order").
+  const legacyFirstState = [
+    '# STATE',
+    '',
+    '### Quick Tasks Completed (v1.0)',
+    '',
+    '| Date | Slug | Scope | Artifacts |',
+    '|------|------|-------|-----------|',
+    '| 2024-06-01 | old | full | — |',
+    '',
+    '### Quick Tasks Completed (v1.1+)',
+    '',
+    '| # | Description | Date | Commit | Directory |',
+    '|---|-------------|------|--------|-----------|',
+    '| 1 | fix typo | 2026-01-01 | abc1234 | — |',
+  ].join('\n');
+
+  test('appendQuickTaskRow locates a milestone-suffixed heading', () => {
+    const result = appendQuickTaskRow(suffixedState, {
+      description: 'probe',
+      date: '2026-08-25',
+      commit: 'deadbee',
+    });
+    assert.equal(result.ok, true, `reason: ${result.reason}`);
+    assert.ok(result.value.content.includes('| 2 | probe | 2026-08-25 | deadbee | — |'));
+    assert.ok(result.value.content.includes('### Quick Tasks Completed (v1.1+)'), 'the suffixed heading itself is untouched');
+  });
+
+  test('resetQuickTaskRows clears a milestone-suffixed heading', () => {
+    const result = resetQuickTaskRows(suffixedState);
+    assert.equal(result.ok, true, `reason: ${result.reason}`);
+    assert.equal(result.value.cleared, 1);
+    assert.ok(!result.value.content.includes('fix typo'));
+    assert.ok(result.value.content.includes('### Quick Tasks Completed (v1.1+)'));
+  });
+
+  test('bare "Quick Tasks Completedness" is NOT matched (word boundary holds)', () => {
+    const notQuick = suffixedState.replace(
+      '### Quick Tasks Completed (v1.1+)',
+      '### Quick Tasks Completedness (v1.1+)',
+    );
+    const result = appendQuickTaskRow(notQuick, { description: 'x', date: '2026-08-25', commit: 'abc' });
+    assert.equal(result.ok, false);
+    assert.equal(result.reason, QUICK_TASKS_SECTION_ABSENT, 'a different section name must still be absent');
+  });
+
+  test('multiple milestone sections: appends to the one holding the canonical table', () => {
+    const result = appendQuickTaskRow(multiMilestoneState, {
+      description: 'second v1.1 task',
+      date: '2025-02-02',
+      commit: '0456def',
+    });
+    assert.equal(result.ok, true, `reason: ${result.reason}`);
+    assert.ok(result.value.content.includes('second v1.1 task'));
+    const v11 = result.value.content.indexOf('### Quick Tasks Completed (v1.1+)');
+    const v10 = result.value.content.indexOf('### Quick Tasks Completed (v1.0)');
+    assert.ok(
+      result.value.content.indexOf('second v1.1 task') > v11 && result.value.content.indexOf('second v1.1 task') < v10,
+      'the row lands in the v1.1+ section (the one whose table matched the canonical schema), not the v1.0 section'
+    );
+    assert.ok(
+      result.value.content.includes('| 1 | legacy v1.0 task | 2024-06-01 | old1234 | — |'),
+      'the v1.0 row is present byte-identical (only the v1.1+ table gained a row)'
+    );
+  });
+
+  test('a legacy-schema section first in document order does not shadow a usable one', () => {
+    const result = appendQuickTaskRow(legacyFirstState, {
+      description: 'new task',
+      date: '2026-08-25',
+      commit: 'deadbee',
+    });
+    assert.equal(result.ok, true, `reason: ${result.reason}`);
+    assert.ok(
+      result.value.content.includes('| 2 | new task | 2026-08-25 | deadbee | — |'),
+      'appends to the v1.1+ canonical table below the legacy v1.0 one'
+    );
+    assert.ok(!result.value.content.includes('unrecognized'), 'no schema complaint when a usable section exists');
+  });
+
+  test('when NO matching section is usable, the error names the real problem (first section\'s)', () => {
+    const onlyLegacy = legacyFirstState.slice(0, legacyFirstState.indexOf('### Quick Tasks Completed (v1.1+)'));
+    const result = appendQuickTaskRow(onlyLegacy, { description: 'x', date: '2026-08-25', commit: 'abc' });
+    assert.equal(result.ok, false);
+    assert.ok(
+      result.reason.includes('unrecognized Quick Tasks schema'),
+      `the failure must describe the legacy table, not claim the section is absent; got: ${result.reason}`
+    );
+  });
+
+  test('#3860 review: a later ## Deferred Items pipe table is NOT the splice target', () => {
+    // The canonical STATE.md layout (templates/state.md + workflows/quick.md)
+    // puts a pipe table AFTER the Quick Tasks section. A section-body
+    // collection that only stops at the next matching heading would swallow
+    // it, and the append's last-table-line scan would splice the quick-task
+    // row into the Deferred Items table.
+    const canonicalLayout = [
+      '# STATE',
+      '',
+      '### Quick Tasks Completed (v1.1+)',
+      '',
+      '| # | Description | Date | Commit | Directory |',
+      '|---|-------------|------|--------|-----------|',
+      '| 1 | fix typo | 2026-01-01 | abc1234 | — |',
+      '',
+      '### Blockers/Concerns',
+      'None',
+      '',
+      '## Deferred Items',
+      '',
+      '| Category | Item | Status | Deferred At | Milestone |',
+      '|----------|------|--------|-------------|-----------|',
+      '| scope | extra thing | deferred | 2026-01-02 | v1.1 |',
+      '',
+    ].join('\n');
+    const result = appendQuickTaskRow(canonicalLayout, {
+      description: 'probe',
+      date: '2026-08-25',
+      commit: 'deadbee',
+    });
+    assert.equal(result.ok, true, `reason: ${result.reason}`);
+    const content = result.value.content;
+    const quickRow = '| 2 | probe | 2026-08-25 | deadbee | — |';
+    assert.ok(content.includes(quickRow), 'the new row exists');
+    assert.ok(
+      content.indexOf(quickRow) < content.indexOf('## Deferred Items'),
+      'the row lands INSIDE the Quick Tasks table, before the Deferred Items section'
+    );
+    assert.ok(
+      content.includes('| scope | extra thing | deferred | 2026-01-02 | v1.1 |'),
+      'the Deferred Items table is byte-identical (no row spliced after its last line)'
+    );
+    const deferred = content.slice(content.indexOf('## Deferred Items'));
+    assert.ok(!deferred.includes(quickRow), 'the Deferred Items section contains no quick-task row');
+  });
+
+  test('#3860 convention: several schema-valid sections — document order (newest-on-top) wins', () => {
+    // The archive flow preserves a recognized header-only table under the old
+    // heading (workflows/complete-milestone.md), so both sections can be
+    // schema-valid. This layer has no active-milestone signal; the pinned
+    // tie-break is document order — first section — matching the issue's own
+    // newest-on-top layout.
+    const bothValid = [
+      '# STATE',
+      '',
+      '### Quick Tasks Completed (v1.1+)',
+      '',
+      '| # | Description | Date | Commit | Directory |',
+      '|---|-------------|------|--------|-----------|',
+      '| 1 | current task | 2026-01-01 | abc1234 | — |',
+      '',
+      '### Quick Tasks Completed (v1.0)',
+      '',
+      '| # | Description | Date | Commit | Directory |',
+      '|---|-------------|------|--------|-----------|',
+      '| 99 | archived task | 2025-01-01 | old1234 | — |',
+    ].join('\n');
+    const result = appendQuickTaskRow(bothValid, {
+      description: 'new task',
+      date: '2026-08-25',
+      commit: 'deadbee',
+    });
+    assert.equal(result.ok, true, `reason: ${result.reason}`);
+    const v11 = result.value.content.indexOf('### Quick Tasks Completed (v1.1+)');
+    const v10 = result.value.content.indexOf('### Quick Tasks Completed (v1.0)');
+    assert.ok(
+      result.value.content.indexOf('| 2 | new task | 2026-08-25 | deadbee | — |') > v11
+        && result.value.content.indexOf('| 2 | new task | 2026-08-25 | deadbee | — |') < v10,
+      'the row lands in the FIRST (newest-on-top) section'
+    );
+  });
+});
+
 // ─── resetQuickTaskRows (#2142) ─────────────────────────────────────────────
 
 describe('resetQuickTaskRows (#2142)', () => {