diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
index 54a835e157..1d4b725bf7 100644
--- a/.github/workflows/e2e-tests.yml
+++ b/.github/workflows/e2e-tests.yml
@@ -8,7 +8,11 @@ jobs:
     # 8-core runner so the 4 Playwright workers (see playwright.config.ts) have
     # CPU headroom alongside the app + ClickHouse + MongoDB — 4 workers
     # over-subscribed the 4-vCPU ubuntu-24.04 runner and caused timeouts.
-    runs-on: 8-core-playwright
+    # RUNNER_E2E is a label or a JSON array of labels. On a smaller
+    # runner, set the E2E_WORKERS variable to 2 as well.
+    runs-on:
+      ${{ startsWith(vars.RUNNER_E2E, '[') && fromJSON(vars.RUNNER_E2E) ||
+      vars.RUNNER_E2E || '8-core-playwright' }}
     timeout-minutes: 15
     permissions:
       contents: read
@@ -25,6 +29,9 @@ jobs:
         uses: ./.github/actions/e2e-setup
 
       - name: Run Playwright tests (full-stack mode)
+        env:
+          # Unset falls back to the default in playwright.config.ts.
+          E2E_WORKERS: ${{ vars.E2E_WORKERS }}
         run: |
           cd packages/app
           yarn test:e2e --shard=${{ matrix.shard }}/4
diff --git a/.github/workflows/release-nightly.yml b/.github/workflows/release-nightly.yml
index 3bd13af222..084a670e75 100644
--- a/.github/workflows/release-nightly.yml
+++ b/.github/workflows/release-nightly.yml
@@ -20,14 +20,18 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
+        # runner is a label, or a JSON array of labels so the RUNNER_* repo
+        # variables can target self-hosted label sets.
         include:
           - arch: amd64
             platform: linux/amd64
             runner: ubuntu-latest
           - arch: arm64
             platform: linux/arm64
-            runner: ubuntu-latest-arm64
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_ARM64 || 'ubuntu-latest-arm64' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -92,11 +96,13 @@ jobs:
         include:
           - arch: amd64
             platform: linux/amd64
-            runner: Large-Runner-x64-32
+            runner: ${{ vars.RUNNER_LARGE_X64 || 'Large-Runner-x64-32' }}
           - arch: arm64
             platform: linux/arm64
-            runner: Large-Runner-ARM64-32
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_LARGE_ARM64 || 'Large-Runner-ARM64-32' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -167,11 +173,13 @@ jobs:
         include:
           - arch: amd64
             platform: linux/amd64
-            runner: Large-Runner-x64-32
+            runner: ${{ vars.RUNNER_LARGE_X64 || 'Large-Runner-x64-32' }}
           - arch: arm64
             platform: linux/arm64
-            runner: Large-Runner-ARM64-32
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_LARGE_ARM64 || 'Large-Runner-ARM64-32' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -244,11 +252,13 @@ jobs:
         include:
           - arch: amd64
             platform: linux/amd64
-            runner: Large-Runner-x64-32
+            runner: ${{ vars.RUNNER_LARGE_X64 || 'Large-Runner-x64-32' }}
           - arch: arm64
             platform: linux/arm64
-            runner: Large-Runner-ARM64-32
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_LARGE_ARM64 || 'Large-Runner-ARM64-32' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index ae52bf1b2e..525c519dc1 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -798,14 +798,18 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
+        # runner is a label, or a JSON array of labels so the RUNNER_* repo
+        # variables can target self-hosted label sets.
         include:
           - arch: amd64
             platform: linux/amd64
             runner: ubuntu-latest
           - arch: arm64
             platform: linux/arm64
-            runner: ubuntu-latest-arm64
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_ARM64 || 'ubuntu-latest-arm64' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -875,11 +879,13 @@ jobs:
         include:
           - arch: amd64
             platform: linux/amd64
-            runner: Large-Runner-x64-32
+            runner: ${{ vars.RUNNER_LARGE_X64 || 'Large-Runner-x64-32' }}
           - arch: arm64
             platform: linux/arm64
-            runner: Large-Runner-ARM64-32
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_LARGE_ARM64 || 'Large-Runner-ARM64-32' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -958,11 +964,13 @@ jobs:
         include:
           - arch: amd64
             platform: linux/amd64
-            runner: Large-Runner-x64-32
+            runner: ${{ vars.RUNNER_LARGE_X64 || 'Large-Runner-x64-32' }}
           - arch: arm64
             platform: linux/arm64
-            runner: Large-Runner-ARM64-32
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_LARGE_ARM64 || 'Large-Runner-ARM64-32' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -1064,11 +1072,13 @@ jobs:
         include:
           - arch: amd64
             platform: linux/amd64
-            runner: Large-Runner-x64-32
+            runner: ${{ vars.RUNNER_LARGE_X64 || 'Large-Runner-x64-32' }}
           - arch: arm64
             platform: linux/arm64
-            runner: Large-Runner-ARM64-32
-    runs-on: ${{ matrix.runner }}
+            runner: ${{ vars.RUNNER_LARGE_ARM64 || 'Large-Runner-ARM64-32' }}
+    runs-on:
+      ${{ startsWith(matrix.runner, '[') && fromJSON(matrix.runner) ||
+      matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6