diff --git a/.github/workflows/1874-diagnose.yml b/.github/workflows/1874-diagnose.yml
index 9c7bd6e5c..a0e9ee0a0 100644
--- a/.github/workflows/1874-diagnose.yml
+++ b/.github/workflows/1874-diagnose.yml
@@ -1,5 +1,18 @@
 name: 1874 Diagnose
 
+# Under the lane rule in #1781:
+#
+#   - Catches: iOS text-entry commit episodes on CI hardware — the dispatched test looped on both
+#     arches, with and without the neighbour test that shares the simulator. An absorbed episode
+#     surfaces as a slow pass, so the cadence is kept for passes too.
+#   - Evidence: the 2026-08-21 dispatch passed 50/50 and still caught an episode (`type-all`
+#     2487 ms across 5 polls) that no PR lane would report; it does not reproduce locally.
+#   - Cost: manual dispatch and the `diagnose/1874-commit-stall` branch only — never a PR or `main`.
+#     One dispatch is four macOS slots, each a runner build plus `iterations` iterations of
+#     simulator time.
+#   - Kill criterion: delete when #2080 closes. It is the last open text-entry question this loop
+#     is the CI reproduction path for, and nothing else reads these artifacts.
+
 on:
   workflow_dispatch:
     inputs:
@@ -7,6 +20,10 @@ on:
         description: 'Loop iterations per job'
         required: false
         default: '25'
+      test:
+        description: 'RunnerTests method to loop'
+        required: false
+        default: testBareTypeUsesTappedInputWhenSoftwareKeyboardIsHidden
   push:
     branches:
       - diagnose/1874-commit-stall
@@ -57,12 +74,17 @@ jobs:
           preferred-device-name: iPhone 17 Pro
 
       - name: Stall loop
+        env:
+          ITERATIONS_INPUT: ${{ github.event.inputs.iterations }}
+          TEST_INPUT: ${{ github.event.inputs.test }}
         run: |
           set -euo pipefail
           XCTESTRUN_PATH="$(find "$AGENT_DEVICE_IOS_RUNNER_DERIVED_PATH/Build/Products" -maxdepth 1 -name '*.xctestrun' -print -quit)"
           test -n "$XCTESTRUN_PATH"
           UDID="${{ steps.ios-simulator.outputs.simulator-udid }}"
-          ITER="${{ github.event.inputs.iterations || '25' }}"
+          ITER="${ITERATIONS_INPUT:-25}"
+          TEST_NAME="${TEST_INPUT:-testBareTypeUsesTappedInputWhenSoftwareKeyboardIsHidden}"
+          mkdir -p .tmp
 
           if [ "${{ matrix.mode }}" = "pair" ]; then
             EXTRA_ONLY_TESTING=(-only-testing:AgentDeviceRunnerUITests/RunnerTests/testBareDelayedTypeFailsWhenTappedInputDisappearsMidCommand)
@@ -73,33 +95,30 @@ jobs:
           sys_prof="$(system_profiler SPHardwareDataType 2>/dev/null | grep -E 'Chip|Cores|Memory' || true)"
           echo "HOST: $sys_prof" | tee stall-summary.txt
 
-          pass=0; fail=0
+          pass=0; skipped=0; failed=0; noresult=0; runfailed=0
           for i in $(seq 1 "$ITER"); do
             LOG=".tmp/stall-run-$i.log"
             set +e
             xcodebuild test-without-building \
               -xctestrun "$XCTESTRUN_PATH" \
               -destination "platform=iOS Simulator,id=$UDID" \
-              -only-testing:AgentDeviceRunnerUITests/RunnerTests/testBareTypeUsesTappedInputWhenSoftwareKeyboardIsHidden \
+              -only-testing:"AgentDeviceRunnerUITests/RunnerTests/$TEST_NAME" \
               ${EXTRA_ONLY_TESTING[@]+"${EXTRA_ONLY_TESTING[@]}"} \
               > "$LOG" 2>&1
             rc=$?
             set -e
-            if grep -q "testBareTypeUsesTappedInputWhenSoftwareKeyboardIsHidden]' passed" "$LOG"; then
-              pass=$((pass+1)); verdict=pass
-            else
-              fail=$((fail+1)); verdict=STALL
-            fi
-            phase="$(grep -o 'phase=type-all durationMs=[0-9.]*' "$LOG" | tail -1)"
-            polls="$(grep -c 'DEBUG-1874] poll' "$LOG" || true)"
-            echo "iter=$i verdict=$verdict rc=$rc $phase polls=$polls" | tee -a stall-summary.txt
-            if [ "$verdict" = "STALL" ]; then
-              grep 'DEBUG-1874' "$LOG" | head -40 | tee -a stall-summary.txt
-              cp "$LOG" ".tmp/stall-failure-$i.log"
-            fi
+            verdict="$(node --experimental-strip-types scripts/diagnose-1874-iteration.ts \
+              "$LOG" "$TEST_NAME" "$i" "$rc")"
+            case "$verdict" in
+              passed) pass=$((pass+1)) ;;
+              skipped) skipped=$((skipped+1)) ;;
+              no-result) noresult=$((noresult+1)) ;;
+              run-failed) runfailed=$((runfailed+1)) ;;
+              *) failed=$((failed+1)) ;;
+            esac
           done
 
-          echo "RESULT arch=${{ matrix.arch }} mode=${{ matrix.mode }}: $pass passed, $fail stalled of $ITER" | tee -a stall-summary.txt
+          echo "RESULT arch=${{ matrix.arch }} mode=${{ matrix.mode }}: $pass passed, $skipped skipped, $failed failed, $noresult no-result, $runfailed run-failed of $ITER" | tee -a stall-summary.txt
 
       - name: Upload stall evidence
         if: always()
@@ -109,5 +128,5 @@ jobs:
           include-hidden-files: true
           path: |
             stall-summary.txt
-            .tmp/stall-failure-*.log
+            .tmp/stall-evidence-*.log
           if-no-files-found: ignore
diff --git a/scripts/__tests__/diagnose-1874-iteration.test.ts b/scripts/__tests__/diagnose-1874-iteration.test.ts
new file mode 100644
index 000000000..350fdf21e
--- /dev/null
+++ b/scripts/__tests__/diagnose-1874-iteration.test.ts
@@ -0,0 +1,157 @@
+import { execFileSync } from 'node:child_process';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { expect, test } from 'vitest';
+import { readIteration, type IterationReport } from '../diagnose-1874-iteration.ts';
+
+const root = path.join(path.dirname(fileURLToPath(import.meta.url)), '../..');
+const script = path.join(root, 'scripts/diagnose-1874-iteration.ts');
+const WORKFLOW = path.join(root, '.github/workflows/1874-diagnose.yml');
+const NAME = 'testBareTypeUsesTappedInputWhenSoftwareKeyboardIsHidden';
+const POLL = '[DEBUG-1874] poll t=1ms observedLen=0 expectedPrefixLen=0';
+const CADENCE = [
+  '[DEBUG-1874] wait start expectedLen=17',
+  POLL,
+  '[DEBUG-1874] wait outcome=settled',
+];
+
+const verdictLine = (test: string, word: string) =>
+  `Test Case '-[X.RunnerTests ${test}]' ${word} (1.0 seconds).`;
+const phases = (typeAllMs: string) =>
+  [
+    `phase=focus durationMs=644.6`,
+    `phase=type-all durationMs=${typeAllMs}`,
+    `phase=total durationMs=7379.7`,
+  ].map((phase) => `AGENT_DEVICE_RUNNER_TEXT_ENTRY_PHASE commandId=c ${phase} chars=17`);
+
+const SHAPES: readonly (Partial<IterationReport> & { name: string; log: string[]; rc?: number })[] =
+  [
+    {
+      name: 'healthy pass',
+      log: [verdictLine(NAME, 'passed'), ...phases('796.1'), ...CADENCE],
+      verdict: 'passed',
+      keepEvidence: false,
+      lines: ['iter=1 verdict=passed rc=0 durationMs=796.1 polls=1'],
+    },
+    {
+      name: 'slow pass — an absorbed episode, which is the evidence #1874 wants',
+      log: [verdictLine(NAME, 'passed'), ...phases('14146.4'), ...CADENCE],
+      verdict: 'passed',
+      keepEvidence: true,
+      lines: ['iter=1 verdict=passed rc=0 durationMs=14146.4 polls=1', ...CADENCE],
+    },
+    {
+      name: 'a pass a tenth of a millisecond over the slow threshold is still slow',
+      log: [verdictLine(NAME, 'passed'), ...phases('2000.1'), ...CADENCE],
+      verdict: 'passed',
+      keepEvidence: true,
+    },
+    {
+      name: 'skipped — an environment flip, not a stall',
+      log: [verdictLine(NAME, 'skipped')],
+      verdict: 'skipped',
+      keepEvidence: true,
+      lines: ['iter=1 verdict=skipped rc=0 durationMs=0 polls=0'],
+    },
+    {
+      name: 'no verdict at all — ours to own, not the product’s',
+      log: ['Executed 0 tests, with 0 failures (0 unexpected) in 0.000 seconds'],
+      verdict: 'no-result',
+      keepEvidence: true,
+    },
+    {
+      name: 'a verdict word this loop does not model is not a stall either',
+      log: [verdictLine(NAME, 'errored')],
+      verdict: 'no-result',
+    },
+    {
+      name: 'pair mode — the neighbour test logs first',
+      log: [
+        verdictLine('testBareDelayedTypeFailsWhenTappedInputDisappearsMidCommand', 'passed'),
+        'AGENT_DEVICE_RUNNER_TEXT_ENTRY_PHASE commandId=n phase=type-all durationMs=5000.0 chars=17',
+        verdictLine(NAME, 'passed'),
+        ...phases('812.0'),
+      ],
+      verdict: 'passed',
+      keepEvidence: false,
+    },
+    {
+      name: 'restarted — the final word is the outcome',
+      log: [verdictLine(NAME, 'failed'), ...phases('900.0'), verdictLine(NAME, 'passed')],
+      verdict: 'passed',
+      keepEvidence: false,
+    },
+    {
+      name: 'measured test passed, xcodebuild did not',
+      log: [verdictLine(NAME, 'passed'), ...phases('796.1'), ...CADENCE],
+      rc: 65,
+      verdict: 'run-failed',
+      keepEvidence: true,
+    },
+    {
+      name: 'louder than the cadence cap',
+      log: [verdictLine(NAME, 'failed'), ...Array.from({ length: 45 }, () => POLL)],
+      verdict: 'failed',
+      keepEvidence: true,
+      lines: [
+        'iter=1 verdict=failed rc=0 durationMs=0 polls=45',
+        ...Array.from({ length: 40 }, () => POLL),
+        '… 5 more DEBUG-1874 lines (full log in the artifact)',
+      ],
+    },
+  ];
+
+test.each(SHAPES)('reads a $name iteration', (shape) => {
+  const report = readIteration(shape.log.join('\n'), NAME, 1, shape.rc ?? 0);
+  expect(report.verdict).toBe(shape.verdict);
+  if (shape.keepEvidence !== undefined) expect(report.keepEvidence).toBe(shape.keepEvidence);
+  if (shape.lines) expect(report.lines).toEqual(shape.lines);
+});
+
+test('the workflow forwards the exit status xcodebuild actually returned', () => {
+  const workflow = fs.readFileSync(WORKFLOW, 'utf8');
+  expect(workflow).toContain('rc=$?');
+  expect(workflow).toMatch(/diagnose-1874-iteration\.ts \\\n\s*"\$LOG" "\$TEST_NAME" "\$i" "\$rc"/);
+});
+
+test('the test name is matched literally, not as a pattern', () => {
+  const log = verdictLine('testAXB', 'passed');
+  expect(readIteration(log, 'testA.B', 1, 0).verdict).toBe('no-result');
+  expect(readIteration(log, 'testAXB', 1, 0).verdict).toBe('passed');
+});
+
+test.each([
+  { label: 'slow pass', rc: 0, verdict: 'passed' },
+  { label: 'nonzero exit over a green measured test', rc: 65, verdict: 'run-failed' },
+])(
+  'the entry point writes, keeps evidence and prints the verdict for a $label',
+  ({ rc, verdict }) => {
+    const cwd = fs.mkdtempSync(path.join(os.tmpdir(), 'diagnose-1874-'));
+    try {
+      fs.mkdirSync(path.join(cwd, '.tmp'));
+      const log = path.join(cwd, 'iteration.log');
+      fs.writeFileSync(
+        log,
+        [verdictLine(NAME, 'passed'), ...phases('14146.4'), ...CADENCE].join('\n'),
+      );
+
+      const printed = execFileSync(
+        process.execPath,
+        ['--experimental-strip-types', script, log, NAME, '7', `${rc}`],
+        { cwd, encoding: 'utf8' },
+      );
+
+      expect(printed).toBe(verdict);
+      expect(fs.readFileSync(path.join(cwd, 'stall-summary.txt'), 'utf8')).toBe(
+        [`iter=7 verdict=${verdict} rc=${rc} durationMs=14146.4 polls=1`, ...CADENCE, ''].join(
+          '\n',
+        ),
+      );
+      expect(fs.existsSync(path.join(cwd, '.tmp', 'stall-evidence-7.log'))).toBe(true);
+    } finally {
+      fs.rmSync(cwd, { recursive: true, force: true });
+    }
+  },
+);
diff --git a/scripts/diagnose-1874-iteration.ts b/scripts/diagnose-1874-iteration.ts
new file mode 100644
index 000000000..6913042a4
--- /dev/null
+++ b/scripts/diagnose-1874-iteration.ts
@@ -0,0 +1,80 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import { pathToFileURL } from 'node:url';
+
+const SLOW_PASS_MS = 2000;
+const CADENCE_LIMIT = 40;
+const SUMMARY = 'stall-summary.txt';
+const EVIDENCE_DIR = '.tmp';
+
+type MeasuredVerdict = 'passed' | 'skipped' | 'failed';
+
+export type IterationReport = {
+  readonly verdict: MeasuredVerdict | 'no-result' | 'run-failed';
+  readonly keepEvidence: boolean;
+  readonly lines: readonly string[];
+};
+
+export function readIteration(
+  log: string,
+  testName: string,
+  iteration: number,
+  rc: number,
+): IterationReport {
+  const lines = log.split('\n');
+  const marker = `${testName}]' `;
+  const word = lines
+    .filter((line) => line.includes(marker))
+    .map((line) => line.slice(line.indexOf(marker) + marker.length).split(' ')[0])
+    .at(-1);
+  const measured = isMeasuredVerdict(word) ? word : 'no-result';
+  const exitContradictsMeasured = rc !== 0 && measured !== 'failed' && measured !== 'no-result';
+  const verdict = exitContradictsMeasured ? 'run-failed' : measured;
+  const durationMs = Number(
+    lines
+      .flatMap((line) => /phase=type-all durationMs=(\d+(?:\.\d+)?)/.exec(line)?.[1] ?? [])
+      .at(-1) ?? 0,
+  );
+  const cadence = lines.filter((line) => line.includes('[DEBUG-1874]'));
+  const keepEvidence = verdict !== 'passed' || durationMs > SLOW_PASS_MS;
+
+  const polls = cadence.filter((line) => line.includes('] poll')).length;
+  const summary = `iter=${iteration} verdict=${verdict} rc=${rc} durationMs=${durationMs} polls=${polls}`;
+  const dropped = cadence.length - CADENCE_LIMIT;
+  return {
+    verdict,
+    keepEvidence,
+    lines: !keepEvidence
+      ? [summary]
+      : [
+          summary,
+          ...cadence.slice(0, CADENCE_LIMIT),
+          ...(dropped > 0 ? [`… ${dropped} more DEBUG-1874 lines (full log in the artifact)`] : []),
+        ],
+  };
+}
+
+function isMeasuredVerdict(word: string | undefined): word is MeasuredVerdict {
+  return word === 'passed' || word === 'skipped' || word === 'failed';
+}
+
+function main(): number {
+  const [logPath, testName, iteration, rc] = process.argv.slice(2);
+  if (!logPath || !testName || !iteration || !rc) {
+    throw new Error('usage: diagnose-1874-iteration.ts <log> <testName> <iteration> <rc>');
+  }
+  const report = readIteration(
+    fs.readFileSync(logPath, 'utf8'),
+    testName,
+    Number(iteration),
+    Number(rc),
+  );
+  fs.appendFileSync(SUMMARY, `${report.lines.join('\n')}\n`);
+  if (report.keepEvidence) {
+    fs.copyFileSync(logPath, path.join(EVIDENCE_DIR, `stall-evidence-${iteration}.log`));
+  }
+  process.stdout.write(report.verdict);
+  return 0;
+}
+
+if (import.meta.url === pathToFileURL(process.argv[1] ?? '').href) process.exit(main());
diff --git a/vitest.config.ts b/vitest.config.ts
index f7303c7e1..5b0814e18 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -153,6 +153,7 @@ export default defineConfig({
             // Parses CI configuration only, so this action guard needs no device or subprocess lane.
             'test/ci/upload-agent-device-artifacts.test.ts',
             'test/ci/upload-artifact-hidden-paths.test.ts',
+            'scripts/__tests__/diagnose-1874-iteration.test.ts',
             // The size reporter is preserved across a base checkout; its entrypoint and imported
             // modules must move as one directory or the Bundle Size lane fails before measuring.
             'test/ci/size-workflow.test.ts',