diff --git a/.github/workflows/ci-cache-warmup-platform-jobs.yml b/.github/workflows/ci-cache-warmup-platform-jobs.yml
index 07fb93918b8..f623fb74a1c 100644
--- a/.github/workflows/ci-cache-warmup-platform-jobs.yml
+++ b/.github/workflows/ci-cache-warmup-platform-jobs.yml
@@ -8,6 +8,7 @@ permissions:
 
 jobs:
   warm-linux-arm:
+    if: github.event_name != 'pull_request'
     concurrency:
       group: ci-cache-warmup-linux-arm-${{ github.event.pull_request.number || github.ref }}
       cancel-in-progress: ${{ github.event_name != 'schedule' }}
@@ -85,6 +86,7 @@ jobs:
           arches: arm64
 
   warm-linux-package-fixtures:
+    if: github.event_name != 'pull_request'
     concurrency:
       group: ci-cache-warmup-linux-package-fixtures-${{ github.event.pull_request.number || github.ref }}
       cancel-in-progress: ${{ github.event_name != 'schedule' }}
diff --git a/.github/workflows/ci-cache-warmup-platforms.yml b/.github/workflows/ci-cache-warmup-platforms.yml
index e8f37a09c78..857fbfaa21e 100644
--- a/.github/workflows/ci-cache-warmup-platforms.yml
+++ b/.github/workflows/ci-cache-warmup-platforms.yml
@@ -45,7 +45,6 @@ on:
       - 'resources/build/icon.ico'
   pull_request:
     paths:
-      - '.github/workflows/ci-cache-warmup.yml'
       - '.github/workflows/ci-cache-warmup-platforms.yml'
       - '.github/workflows/ci-cache-warmup-platform-jobs.yml'
 
diff --git a/.github/workflows/ci-cache-warmup.yml b/.github/workflows/ci-cache-warmup.yml
index 8487d95ef34..882dfac0bab 100644
--- a/.github/workflows/ci-cache-warmup.yml
+++ b/.github/workflows/ci-cache-warmup.yml
@@ -50,8 +50,6 @@ on:
   pull_request:
     paths:
       - '.github/workflows/ci-cache-warmup.yml'
-      - '.github/workflows/ci-cache-warmup-platform-jobs.yml'
-      - '.github/workflows/ci-cache-warmup-platforms.yml'
       - '.github/actions/prepare-headless-compiler/**'
       - 'config/scripts/headless-detector-compiler-cache.mjs'
       - '.github/actions/prepare-wayland-clipboard/**'
diff --git a/config/scripts/ci-dependency-download-cache.test.mjs b/config/scripts/ci-dependency-download-cache.test.mjs
index 8db466b4637..0bcfefa5edb 100644
--- a/config/scripts/ci-dependency-download-cache.test.mjs
+++ b/config/scripts/ci-dependency-download-cache.test.mjs
@@ -2,6 +2,7 @@ import { readFileSync } from 'node:fs'
 import { runInNewContext } from 'node:vm'
 import { describe, expect, it } from 'vitest'
 import { parse } from 'yaml'
+import { classifyPrJobs } from './pr-code-change-scope.mjs'
 
 const read = (path) => parse(readFileSync(path, 'utf8'))
 const workflow = (name) => read(`.github/workflows/${name}.yml`)
@@ -300,6 +301,116 @@ describe('CI dependency download caches', () => {
     }
   })
 
+  it('keeps PR warmer validation within the workflow family that runs it', () => {
+    const shared = workflow('ci-cache-warmup')
+    const platforms = workflow('ci-cache-warmup-platforms')
+    expect(shared.on.pull_request.paths).toEqual([
+      '.github/workflows/ci-cache-warmup.yml',
+      '.github/actions/prepare-headless-compiler/**',
+      'config/scripts/headless-detector-compiler-cache.mjs',
+      '.github/actions/prepare-wayland-clipboard/**'
+    ])
+    expect(platforms.on.pull_request.paths).toEqual([
+      '.github/workflows/ci-cache-warmup-platforms.yml',
+      '.github/workflows/ci-cache-warmup-platform-jobs.yml'
+    ])
+    expect(shared.jobs['warm-platforms'].uses).toBe(platforms.jobs['warm-platforms'].uses)
+    expect(shared.on.schedule).toEqual([{ cron: '41 */6 * * *' }])
+    expect(shared.on).toHaveProperty('workflow_dispatch')
+    for (const producer of [shared, platforms]) {
+      expect(producer.on.push.branches).toEqual(['main'])
+      expect(producer.on.push.paths).toEqual(
+        expect.arrayContaining([
+          '.github/workflows/ci-cache-warmup.yml',
+          '.github/workflows/ci-cache-warmup-platforms.yml',
+          '.github/workflows/ci-cache-warmup-platform-jobs.yml',
+          '.github/actions/install-node-dependencies/**',
+          '.github/actions/prepare-native-runtime/**',
+          'pnpm-lock.yaml'
+        ])
+      )
+    }
+  })
+
+  it.each([
+    ['pull_request', false, false],
+    ['push', true, false],
+    ['schedule', true, true],
+    ['workflow_dispatch', true, true]
+  ])('retains cache producers and Windows validation on %s', (event, armRuns, sharedPlatforms) => {
+    const shared = workflow('ci-cache-warmup')
+    const platforms = read(workflow('ci-cache-warmup-platforms').jobs['warm-platforms'].uses)
+    const context = { github: { event_name: event } }
+    expect(runInNewContext(platforms.jobs['warm-linux-arm'].if, context)).toBe(armRuns)
+    expect(runInNewContext(shared.jobs['warm-platforms'].if, context)).toBe(sharedPlatforms)
+    expect(shared.jobs.warm.if).toBeUndefined()
+    expect(platforms.jobs['warm-windows'].if).toBeUndefined()
+    expect(platforms.jobs['warm-windows'].strategy.matrix.os).toEqual([
+      'windows-2022',
+      'windows-11-arm'
+    ])
+  })
+
+  it('validates the omitted ARM warmer preparation in the real PR consumers', () => {
+    const platforms = read(workflow('ci-cache-warmup-platforms').jobs['warm-platforms'].uses)
+    const warm = platforms.jobs['warm-linux-arm']
+    const pr = workflow('pr')
+    const units = workflow('unit-tests').jobs.test
+    const installer = './.github/actions/install-node-dependencies'
+    const warmInstall = warm.steps.find((step) => step.uses === installer)
+    const unitInstall = units.steps.find((step) => step.uses === installer)
+    expect(warm['runs-on']).toBe('ubuntu-24.04-arm')
+    expect(pr.jobs.preflight['runs-on']).toBe(warm['runs-on'])
+    expect(pr.jobs.test.with.runner).toBe(warm['runs-on'])
+    expect(units['runs-on']).toBe('${{ inputs.runner }}')
+    expect(JSON.parse(pr.jobs.test.with.node_versions)).toEqual(['24'])
+    expect(warmInstall.if).toBeUndefined()
+    expect(unitInstall.if).toBeUndefined()
+    expect(warmInstall.with['native-runtime']).toBe('node')
+    expect(unitInstall.with['native-runtime']).toBe(warmInstall.with['native-runtime'])
+    expect(warmInstall.with['node-version']).toBe('24')
+    expect(unitInstall.with['node-version']).toBe('${{ matrix.node }}')
+    expect(unitInstall.with['cache-electron-package']).toBe(
+      warmInstall.with['cache-electron-package']
+    )
+    const preflightInstalls = pr.jobs.preflight.steps.filter((step) => step.uses === installer)
+    expect(preflightInstalls.map((step) => step.if)).toEqual([
+      "needs.code_paths.outputs.mobile_dependencies != 'true'",
+      "needs.code_paths.outputs.mobile_dependencies == 'true'"
+    ])
+    for (const step of preflightInstalls) {
+      expect(step.with['native-runtime']).toBe('node')
+      expect(step.with['node-version']).toBe('24')
+    }
+    const populate = 'node config/scripts/install-electron-package-binary.mjs'
+    const unitPopulate = units.steps.find((step) => step.run === populate)
+    expect(unitPopulate.if).toBeUndefined()
+    expect(warm.steps.map((step) => step.uses ?? step.run)).toEqual([
+      'actions/checkout@v6',
+      installer,
+      populate,
+      'node config/scripts/ensure-native-runtime.mjs --check-only'
+    ])
+    const native = read('.github/actions/prepare-native-runtime/action.yml')
+    const identity = native.runs.steps.find((step) => step.id === 'native-cache-scope')
+    const inputs = [...identity.env.NATIVE_SOURCE_HASH.matchAll(/'([^']+)'/g)].map(
+      (match) => match[1]
+    )
+    for (const path of [
+      ...inputs,
+      '.github/actions/install-node-dependencies/action.yml',
+      ...workflow('ci-cache-warmup-platforms').on.pull_request.paths,
+      '.github/workflows/ci-cache-warmup.yml'
+    ]) {
+      expect(classifyPrJobs([path], { allowMobileCiTools: true }), path).toMatchObject({
+        static_analysis: true,
+        typecheck: true,
+        test: true,
+        mobile_ci_tools: false
+      })
+    }
+  })
+
   it('restores Windows packaging downloads from the release cache without a PR upload', () => {
     const packaging = workflow('pr').jobs.package_windows
     const restore = packaging.steps.find((step) => step.name === 'Cache electron-builder downloads')
diff --git a/config/scripts/linux-package-fixture-cache.test.mjs b/config/scripts/linux-package-fixture-cache.test.mjs
index 6c677f0abc8..81465a38a29 100644
--- a/config/scripts/linux-package-fixture-cache.test.mjs
+++ b/config/scripts/linux-package-fixture-cache.test.mjs
@@ -1,9 +1,11 @@
 import { chmodSync, mkdtempSync, mkdirSync, readFileSync, rmSync, writeFileSync } from 'node:fs'
 import { tmpdir } from 'node:os'
+import { runInNewContext } from 'node:vm'
 import { delimiter, join } from 'node:path'
 import { afterEach, describe, expect, it } from 'vitest'
 import { parse } from 'yaml'
 import { runProcessSync } from '@orca/process-host'
+import { classifyPrJobs } from './pr-code-change-scope.mjs'
 
 const action = parse(
   readFileSync('.github/actions/prepare-linux-package-fixture/action.yml', 'utf8')
@@ -132,3 +134,45 @@ it('uses exact context/platform keys and the same restore-only action in package
       .every((step) => step.with['save-cache'] === "${{ github.event_name != 'pull_request' }}")
   ).toBe(true)
 })
+
+it.each([
+  ['pull_request', false],
+  ['push', true],
+  ['schedule', true],
+  ['workflow_dispatch', true]
+])('keeps fixture seeding available without a redundant PR runner on %s', (event, runs) => {
+  const source = workflow('ci-cache-warmup-platforms').jobs['warm-platforms'].uses
+  const warm = parse(readFileSync(source, 'utf8')).jobs['warm-linux-package-fixtures']
+  const context = { github: { event_name: event } }
+  expect(warm['runs-on']).toBe('ubuntu-latest')
+  expect(warm.steps.map((step) => step.uses)).toEqual([
+    'actions/checkout@v6',
+    './.github/actions/prepare-linux-package-fixture',
+    './.github/actions/prepare-linux-package-fixture',
+    './.github/actions/prepare-linux-package-fixture'
+  ])
+  expect(runInNewContext(warm.if, context)).toBe(runs)
+  for (const step of warm.steps.slice(1)) {
+    expect(runInNewContext(step.with['save-cache'].slice(3, -2), context)).toBe(runs)
+  }
+  const consumers = workflow('pr').jobs.package.steps.filter((step) =>
+    step.uses?.endsWith('/prepare-linux-package-fixture')
+  )
+  expect(consumers.every((step) => step.with['save-cache'] === undefined)).toBe(true)
+  expect(consumers.map((step) => step.with.fixture)).toEqual(
+    warm.steps.slice(1).map((step) => step.with.fixture)
+  )
+})
+
+it.each([
+  '.github/actions/prepare-linux-package-fixture/action.yml',
+  'config/docker/daemon-shutdown-descendants/Dockerfile',
+  'config/docker/headless-serve-shutdown/Dockerfile',
+  'config/docker/cli-launch-contract/Dockerfile'
+])('validates a changed fixture in Linux packaging: %s', (file) => {
+  expect(classifyPrJobs([file])).toMatchObject({
+    test: true,
+    package: true,
+    package_windows: false
+  })
+})