diff --git a/.github/workflows/backend.yml b/.github/workflows/backend.yml
index b09e14d90..3afe0c681 100644
--- a/.github/workflows/backend.yml
+++ b/.github/workflows/backend.yml
@@ -35,11 +35,13 @@ jobs:
       matrix-singlearch: ${{ steps.set-matrix.outputs['matrix-singlearch'] }}
       matrix-multiarch: ${{ steps.set-matrix.outputs['matrix-multiarch'] }}
       matrix-darwin: ${{ steps.set-matrix.outputs['matrix-darwin'] }}
-      merge-matrix: ${{ steps.set-matrix.outputs['merge-matrix'] }}
+      merge-matrix-multiarch: ${{ steps.set-matrix.outputs['merge-matrix-multiarch'] }}
+      merge-matrix-singlearch: ${{ steps.set-matrix.outputs['merge-matrix-singlearch'] }}
       has-backends-singlearch: ${{ steps.set-matrix.outputs['has-backends-singlearch'] }}
       has-backends-multiarch: ${{ steps.set-matrix.outputs['has-backends-multiarch'] }}
       has-backends-darwin: ${{ steps.set-matrix.outputs['has-backends-darwin'] }}
-      has-merges: ${{ steps.set-matrix.outputs['has-merges'] }}
+      has-merges-multiarch: ${{ steps.set-matrix.outputs['has-merges-multiarch'] }}
+      has-merges-singlearch: ${{ steps.set-matrix.outputs['has-merges-singlearch'] }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
@@ -138,15 +140,21 @@ jobs:
       max-parallel: 8
       matrix: ${{ fromJson(needs.generate-matrix.outputs['matrix-singlearch']) }}
 
-  # Merge per-arch digests into manifest lists. Depends ONLY on
-  # backend-jobs-multiarch — single-arch builds are independent and slow.
-  # Without this split, a 6h CUDA-12 single-arch job would gate the merge,
-  # leaving multi-arch digests untagged on quay long enough for quay's
-  # garbage collector to reap them and the merge step to fail with
-  # "manifest not found".
-  backend-merge-jobs:
+  # Apply tags to per-arch digests via `imagetools create`. Split into two
+  # jobs that mirror the build split so each merge waits ONLY on its
+  # corresponding build matrix:
+  #
+  #   - backend-merge-jobs-multiarch  needs backend-jobs-multiarch  (~2-3h)
+  #   - backend-merge-jobs-singlearch needs backend-jobs-singlearch (up to ~6h)
+  #
+  # If a single shared merge job depended on both, slow CUDA singlearch
+  # builds would block multiarch merges long enough for quay's GC to reap
+  # the multiarch per-arch digests (the bug fixed by PR #9746). Singletons
+  # also need a merge step because backend_build.yml pushes by canonical
+  # digest only — no tags are applied at build time.
+  backend-merge-jobs-multiarch:
     needs: [generate-matrix, backend-jobs-multiarch]
-    if: needs.generate-matrix.outputs['has-merges'] == 'true'
+    if: needs.generate-matrix.outputs['has-merges-multiarch'] == 'true'
     uses: ./.github/workflows/backend_merge.yml
     with:
       tag-latest: ${{ matrix.tag-latest }}
@@ -158,7 +166,23 @@ jobs:
       quayPassword: ${{ secrets.LOCALAI_REGISTRY_PASSWORD }}
     strategy:
       fail-fast: false
-      matrix: ${{ fromJson(needs.generate-matrix.outputs['merge-matrix']) }}
+      matrix: ${{ fromJson(needs.generate-matrix.outputs['merge-matrix-multiarch']) }}
+
+  backend-merge-jobs-singlearch:
+    needs: [generate-matrix, backend-jobs-singlearch]
+    if: needs.generate-matrix.outputs['has-merges-singlearch'] == 'true'
+    uses: ./.github/workflows/backend_merge.yml
+    with:
+      tag-latest: ${{ matrix.tag-latest }}
+      tag-suffix: ${{ matrix.tag-suffix }}
+    secrets:
+      dockerUsername: ${{ secrets.DOCKERHUB_USERNAME }}
+      dockerPassword: ${{ secrets.DOCKERHUB_PASSWORD }}
+      quayUsername: ${{ secrets.LOCALAI_REGISTRY_USERNAME }}
+      quayPassword: ${{ secrets.LOCALAI_REGISTRY_PASSWORD }}
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJson(needs.generate-matrix.outputs['merge-matrix-singlearch']) }}
 
   backend-jobs-darwin:
     needs: generate-matrix
diff --git a/.github/workflows/backend_build.yml b/.github/workflows/backend_build.yml
index 524615baa..cc7a8eaa6 100644
--- a/.github/workflows/backend_build.yml
+++ b/.github/workflows/backend_build.yml
@@ -228,11 +228,18 @@ jobs:
           digest="${{ steps.build.outputs.digest }}"
           touch "/tmp/digests/${digest#sha256:}"
 
+      # Artifact name uses a `--` separator between tag-suffix and platform-tag
+      # to avoid prefix collisions during the merge job's pattern-based download.
+      # Tag-suffixes are not prefix-disjoint (e.g. -gpu-nvidia-cuda-12-vllm is a
+      # prefix of -gpu-nvidia-cuda-12-vllm-omni); a single `-` separator plus the
+      # merge-side `digests<tag-suffix>-*` glob would let one merge over-match
+      # the other backend's artifacts. The `-single` placeholder for empty
+      # platform-tag (single-arch entries) keeps the artifact name non-trailing.
       - name: Upload digest artifact
         if: github.event_name != 'pull_request'
         uses: actions/upload-artifact@v4
         with:
-          name: digests${{ inputs.tag-suffix }}-${{ inputs.platform-tag }}
+          name: digests${{ inputs.tag-suffix }}--${{ inputs.platform-tag || 'single' }}
           path: /tmp/digests/*
           if-no-files-found: error
           retention-days: 1
diff --git a/.github/workflows/backend_merge.yml b/.github/workflows/backend_merge.yml
index 9243dae28..080b0c113 100644
--- a/.github/workflows/backend_merge.yml
+++ b/.github/workflows/backend_merge.yml
@@ -34,10 +34,14 @@ jobs:
     env:
       quay_username: ${{ secrets.quayUsername }}
     steps:
+      # `--` separator anchors the glob so we don't over-match sibling
+      # backends whose tag-suffix happens to be a prefix of ours
+      # (e.g. -cpu-vllm vs -cpu-vllm-omni). Must stay in sync with the
+      # upload-artifact name in backend_build.yml.
       - name: Download digests
         uses: actions/download-artifact@v4
         with:
-          pattern: digests${{ inputs.tag-suffix }}-*
+          pattern: digests${{ inputs.tag-suffix }}--*
           merge-multiple: true
           path: /tmp/digests
 
diff --git a/.github/workflows/backend_pr.yml b/.github/workflows/backend_pr.yml
index cf7a96a99..9b0aba310 100644
--- a/.github/workflows/backend_pr.yml
+++ b/.github/workflows/backend_pr.yml
@@ -14,11 +14,13 @@ jobs:
       matrix-singlearch: ${{ steps.set-matrix.outputs['matrix-singlearch'] }}
       matrix-multiarch: ${{ steps.set-matrix.outputs['matrix-multiarch'] }}
       matrix-darwin: ${{ steps.set-matrix.outputs['matrix-darwin'] }}
-      merge-matrix: ${{ steps.set-matrix.outputs['merge-matrix'] }}
+      merge-matrix-multiarch: ${{ steps.set-matrix.outputs['merge-matrix-multiarch'] }}
+      merge-matrix-singlearch: ${{ steps.set-matrix.outputs['merge-matrix-singlearch'] }}
       has-backends-singlearch: ${{ steps.set-matrix.outputs['has-backends-singlearch'] }}
       has-backends-multiarch: ${{ steps.set-matrix.outputs['has-backends-multiarch'] }}
       has-backends-darwin: ${{ steps.set-matrix.outputs['has-backends-darwin'] }}
-      has-merges: ${{ steps.set-matrix.outputs['has-merges'] }}
+      has-merges-multiarch: ${{ steps.set-matrix.outputs['has-merges-multiarch'] }}
+      has-merges-singlearch: ${{ steps.set-matrix.outputs['has-merges-singlearch'] }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
@@ -97,12 +99,12 @@ jobs:
       fail-fast: true
       max-parallel: 8
       matrix: ${{ fromJson(needs.generate-matrix.outputs['matrix-singlearch']) }}
-  backend-merge-jobs:
+  backend-merge-jobs-multiarch:
     needs: [generate-matrix, backend-jobs-multiarch]
     # backend_merge.yml's push-side steps are all gated on
     # github.event_name != 'pull_request', so on a PR the merge job would
     # do nothing. Skip it entirely to avoid spinning up an empty runner.
-    if: github.event_name != 'pull_request' && needs.generate-matrix.outputs['has-merges'] == 'true'
+    if: github.event_name != 'pull_request' && needs.generate-matrix.outputs['has-merges-multiarch'] == 'true'
     uses: ./.github/workflows/backend_merge.yml
     with:
       tag-latest: ${{ matrix.tag-latest }}
@@ -112,7 +114,21 @@ jobs:
       quayPassword: ${{ secrets.LOCALAI_REGISTRY_PASSWORD }}
     strategy:
       fail-fast: false
-      matrix: ${{ fromJson(needs.generate-matrix.outputs['merge-matrix']) }}
+      matrix: ${{ fromJson(needs.generate-matrix.outputs['merge-matrix-multiarch']) }}
+
+  backend-merge-jobs-singlearch:
+    needs: [generate-matrix, backend-jobs-singlearch]
+    if: github.event_name != 'pull_request' && needs.generate-matrix.outputs['has-merges-singlearch'] == 'true'
+    uses: ./.github/workflows/backend_merge.yml
+    with:
+      tag-latest: ${{ matrix.tag-latest }}
+      tag-suffix: ${{ matrix.tag-suffix }}
+    secrets:
+      quayUsername: ${{ secrets.LOCALAI_REGISTRY_USERNAME }}
+      quayPassword: ${{ secrets.LOCALAI_REGISTRY_PASSWORD }}
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJson(needs.generate-matrix.outputs['merge-matrix-singlearch']) }}
   backend-jobs-darwin:
     needs: generate-matrix
     uses: ./.github/workflows/backend_build_darwin.yml
diff --git a/scripts/changed-backends.js b/scripts/changed-backends.js
index 95d9e356f..d5dc309d3 100644
--- a/scripts/changed-backends.js
+++ b/scripts/changed-backends.js
@@ -128,11 +128,15 @@ async function getChangedFilesForPush(event) {
   return res.data.files.map(f => f.filename);
 }
 
-// Group filtered linux matrix entries by tag-suffix and emit a merge-matrix
-// entry for any tag-suffix that appears 2+ times. That's the trigger for
-// "this backend has multiple per-arch legs and we need a manifest list".
-// Singletons aren't merged — single-arch backends push by digest and don't
-// need a manifest list assembled across legs.
+// Group matrix entries by tag-suffix and emit a merge-matrix entry per group.
+// Both multi-leg groups (per-arch fan-out) and singletons get one entry each:
+// the build job pushes by digest only with no tags applied, so every backend
+// needs a downstream merge step to apply its tags via `imagetools create`,
+// regardless of how many per-arch legs feed it. Callers split entries by
+// arch class first (see splitByArch) and call this once per class so the
+// resulting matrices can be wired to merge jobs that `needs:` only their
+// corresponding build matrix — preventing slow single-arch builds from
+// gating multi-arch merges (the bug fixed in PR #9746).
 function computeMergeMatrix(entries) {
   const groups = new Map();
   for (const item of entries) {
@@ -143,7 +147,6 @@ function computeMergeMatrix(entries) {
   }
   const include = [];
   for (const [tagSuffix, group] of groups) {
-    if (group.length < 2) continue;
     // tag-latest must agree across legs — they're going to publish under
     // the same final tag, so disagreeing on whether it's also the :latest
     // tag is an authoring bug. Warn loudly so a Task 2.5 fan-out typo is
@@ -177,17 +180,21 @@ function splitByArch(entries) {
 
 function emitFullMatrix() {
   const { multiarch, singlearch } = splitByArch(includes);
-  const mergeMatrix = computeMergeMatrix(includes);
-  const hasMerges = mergeMatrix.include.length > 0 ? 'true' : 'false';
+  const mergeMatrixMultiarch = computeMergeMatrix(multiarch);
+  const mergeMatrixSinglearch = computeMergeMatrix(singlearch);
+  const hasMergesMultiarch = mergeMatrixMultiarch.include.length > 0 ? 'true' : 'false';
+  const hasMergesSinglearch = mergeMatrixSinglearch.include.length > 0 ? 'true' : 'false';
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `run-all=true\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-backends-singlearch=${singlearch.length > 0 ? 'true' : 'false'}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-backends-multiarch=${multiarch.length > 0 ? 'true' : 'false'}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-backends-darwin=true\n`);
-  fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-merges=${hasMerges}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-merges-multiarch=${hasMergesMultiarch}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-merges-singlearch=${hasMergesSinglearch}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `matrix-singlearch=${JSON.stringify({ include: singlearch })}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `matrix-multiarch=${JSON.stringify({ include: multiarch })}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `matrix-darwin=${JSON.stringify({ include: includesDarwin })}\n`);
-  fs.appendFileSync(process.env.GITHUB_OUTPUT, `merge-matrix=${JSON.stringify(mergeMatrix)}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `merge-matrix-multiarch=${JSON.stringify(mergeMatrixMultiarch)}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `merge-matrix-singlearch=${JSON.stringify(mergeMatrixSinglearch)}\n`);
   for (const backend of allBackendPaths.keys()) {
     fs.appendFileSync(process.env.GITHUB_OUTPUT, `${backend}=true\n`);
   }
@@ -218,18 +225,22 @@ function emitFilteredMatrix(changedFiles) {
   console.log("Has multi-arch backends?:", hasBackendsMultiarch);
   console.log("Has Darwin backends?:", hasBackendsDarwin);
 
-  const mergeMatrix = computeMergeMatrix(filtered);
-  const hasMerges = mergeMatrix.include.length > 0 ? 'true' : 'false';
+  const mergeMatrixMultiarch = computeMergeMatrix(multiarch);
+  const mergeMatrixSinglearch = computeMergeMatrix(singlearch);
+  const hasMergesMultiarch = mergeMatrixMultiarch.include.length > 0 ? 'true' : 'false';
+  const hasMergesSinglearch = mergeMatrixSinglearch.include.length > 0 ? 'true' : 'false';
 
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `run-all=false\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-backends-singlearch=${hasBackendsSinglearch}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-backends-multiarch=${hasBackendsMultiarch}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-backends-darwin=${hasBackendsDarwin}\n`);
-  fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-merges=${hasMerges}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-merges-multiarch=${hasMergesMultiarch}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `has-merges-singlearch=${hasMergesSinglearch}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `matrix-singlearch=${JSON.stringify({ include: singlearch })}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `matrix-multiarch=${JSON.stringify({ include: multiarch })}\n`);
   fs.appendFileSync(process.env.GITHUB_OUTPUT, `matrix-darwin=${JSON.stringify({ include: filteredDarwin })}\n`);
-  fs.appendFileSync(process.env.GITHUB_OUTPUT, `merge-matrix=${JSON.stringify(mergeMatrix)}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `merge-matrix-multiarch=${JSON.stringify(mergeMatrixMultiarch)}\n`);
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `merge-matrix-singlearch=${JSON.stringify(mergeMatrixSinglearch)}\n`);
 
   // Per-backend boolean outputs
   for (const [backend, pathPrefix] of allBackendPaths) {