diff --git a/browse/test/gstack-config.test.ts b/browse/test/gstack-config.test.ts
index a00af6096..958ce88dc 100644
--- a/browse/test/gstack-config.test.ts
+++ b/browse/test/gstack-config.test.ts
@@ -151,6 +151,29 @@ describe('gstack-config', () => {
     expect(content).toContain('skip_eng_review:');
   });
 
+  // ─── codex_reviews (paid-calls switch: reject-on-set, preserve existing) ──
+  test('codex_reviews defaults to enabled', () => {
+    const { exitCode, stdout } = run(['get', 'codex_reviews']);
+    expect(exitCode).toBe(0);
+    expect(stdout).toBe('enabled');
+  });
+
+  test('codex_reviews accepts enabled and disabled', () => {
+    expect(run(['set', 'codex_reviews', 'disabled']).exitCode).toBe(0);
+    expect(run(['get', 'codex_reviews']).stdout).toBe('disabled');
+    expect(run(['set', 'codex_reviews', 'enabled']).exitCode).toBe(0);
+    expect(run(['get', 'codex_reviews']).stdout).toBe('enabled');
+  });
+
+  test('codex_reviews rejects an invalid value and preserves the existing one', () => {
+    run(['set', 'codex_reviews', 'disabled']);
+    const { exitCode, stderr } = run(['set', 'codex_reviews', 'disabledd']);
+    expect(exitCode).not.toBe(0); // rejected, not warn-and-default
+    expect(stderr).toContain('not recognized');
+    // existing value must be untouched — a typo never silently flips paid Codex on/off
+    expect(run(['get', 'codex_reviews']).stdout).toBe('disabled');
+  });
+
   test('header written only once, not duplicated on second set', () => {
     run(['set', 'foo', 'bar']);
     run(['set', 'baz', 'qux']);
diff --git a/test/skill-validation.test.ts b/test/skill-validation.test.ts
index fb1ec5bf4..e7def7dfa 100644
--- a/test/skill-validation.test.ts
+++ b/test/skill-validation.test.ts
@@ -1386,15 +1386,16 @@ describe('Codex skill', () => {
     expect(content).toContain('Adversarial review (always-on)');
     // Always-on: both Claude and Codex adversarial
     expect(content).toContain('Claude adversarial subagent (always runs)');
-    expect(content).toContain('Codex adversarial challenge (always runs when available)');
+    expect(content).toContain('Codex adversarial challenge (runs whenever');
     // Claude adversarial subagent dispatch
     expect(content).toContain('Agent tool');
     expect(content).toContain('FIXABLE');
     expect(content).toContain('INVESTIGATE');
-    // Codex availability check
-    expect(content).toContain('CODEX_NOT_AVAILABLE');
-    // OLD_CFG only gates Codex, not Claude
-    expect(content).toContain('skip Codex passes only');
+    // Probe-based availability via the shared codexPreflight() (install + auth)
+    expect(content).toContain('CODEX_MODE');
+    expect(content).toContain('command -v codex'); // install check kept literal
+    // codex_reviews=disabled gates Codex passes only; Claude adversarial still runs
+    expect(content).toContain('skip the Codex passes ONLY');
     // Review log
     expect(content).toContain('adversarial-review');
     expect(content).toContain('reasoning_effort="high"');
@@ -1449,6 +1450,43 @@ describe('Codex skill', () => {
     expect(content).toContain('codex exec');
   });
 
+  // D5 regression guard: the Codex outside voice is default-on, not opt-in. A future
+  // gen-skill-docs change must not silently reintroduce the "Want an outside voice?"
+  // AskUserQuestion. The CODEX_PLAN_REVIEW content renders into each skill's
+  // sections/review-sections.md (the skeleton points at it). plan-design-review uses
+  // DESIGN_OUTSIDE_VOICES, not CODEX_PLAN_REVIEW, so it is excluded here.
+  test('plan reviews run the Codex outside voice default-on (no opt-in question)', () => {
+    for (const skill of ['plan-eng-review', 'plan-ceo-review', 'plan-devex-review']) {
+      const content = fs.readFileSync(
+        path.join(ROOT, skill, 'sections', 'review-sections.md'), 'utf-8');
+      expect(content).not.toContain('Want an outside voice');
+      expect(content).toContain('Outside Voice — Independent Plan Challenge (default-on)');
+      expect(content).toContain('CODEX_MODE');
+      expect(content).toContain('command -v codex'); // preflight install check (e2e relies on it)
+    }
+  });
+
+  test('/document-release includes the default-on Codex documentation review', () => {
+    // The doc-review renders into the carved release-body section (kept out of the
+    // always-loaded skeleton to respect the skeleton-byte budget).
+    const content = fs.readFileSync(
+      path.join(ROOT, 'document-release', 'sections', 'release-body.md'), 'utf-8');
+    expect(content).toContain('Codex Documentation Review (default-on)');
+    expect(content).toContain('CODEX_MODE');
+    expect(content).toContain('codex-doc-review');
+  });
+
+  test('codex-host document-release does NOT contain the Codex doc review', () => {
+    // .agents/ is gitignored — generate on demand (codex never invokes itself)
+    Bun.spawnSync(['bun', 'run', 'scripts/gen-skill-docs.ts', '--host', 'codex'], {
+      cwd: ROOT, stdout: 'pipe', stderr: 'pipe',
+    });
+    const content = fs.readFileSync(
+      path.join(ROOT, '.agents', 'skills', 'gstack-document-release', 'SKILL.md'), 'utf-8');
+    expect(content).not.toContain('Codex Documentation Review');
+    expect(content).not.toContain('codex-doc-review');
+  });
+
   test('codex review invocations avoid the prompt plus --base argument shape', () => {
     for (const rel of ['codex/SKILL.md', 'review/SKILL.md', 'ship/SKILL.md']) {
       // ship's codex command moved into sections/adversarial.md (T9 carve).