diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 71401593c..12f46c563 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -116,6 +116,7 @@ jobs:
             sd-${{ env.BRANCH_NAME }}-${{ steps.commit.outputs.short }}-bin-${{ steps.system-info.outputs.OS_TYPE }}-${{ steps.system-info.outputs.OS_NAME }}-${{ steps.system-info.outputs.OS_VERSION }}-${{ steps.system-info.outputs.CPU_ARCH }}.zip
 
   ubuntu-latest-cmake-vulkan:
+    if: ${{ github.event_name == 'workflow_dispatch' }}
     runs-on: ubuntu-latest
 
     steps:
@@ -180,7 +181,7 @@ jobs:
 
   build-and-push-docker-images:
     name: Build and push container images
-    if: ${{ github.event_name != 'pull_request' }}
+    if: ${{ github.event_name == 'workflow_dispatch' }}
     runs-on: ${{ matrix.runner }}
 
     permissions:
@@ -341,13 +342,10 @@ jobs:
 
     strategy:
       matrix:
-        include:
-          - build: "cpu"
-            defines: "-DGGML_NATIVE=OFF -DSD_BUILD_SHARED_LIBS=ON -DSD_BUILD_SHARED_GGML_LIB=ON -DGGML_BACKEND_DL=ON -DGGML_CPU_ALL_VARIANTS=ON"
-          - build: "cuda12"
-            defines: "-DSD_CUDA=ON -DSD_BUILD_SHARED_LIBS=ON -DCMAKE_CUDA_ARCHITECTURES='61;70;75;80;86;89;90;100;120' -DCMAKE_CUDA_FLAGS='-Xcudafe \"--diag_suppress=177\" -Xcudafe \"--diag_suppress=550\"' -DGGML_NATIVE=OFF -DSD_BUILD_SHARED_GGML_LIB=ON -DGGML_BACKEND_DL=ON -DGGML_CPU_ALL_VARIANTS=ON"
-          - build: "vulkan"
-            defines: "-DSD_VULKAN=ON -DSD_BUILD_SHARED_LIBS=ON -DGGML_NATIVE=OFF -DSD_BUILD_SHARED_GGML_LIB=ON -DGGML_BACKEND_DL=ON -DGGML_CPU_ALL_VARIANTS=ON"
+        # cuda12 and vulkan are dispatch-only: nothing here ships (our
+        # prebuilts come from unsloth-sd-prebuilt.yml) and they cost 142 min.
+        include: ${{ github.event_name == 'workflow_dispatch' && fromJSON('[{"build":"cpu","defines":"-DGGML_NATIVE=OFF -DSD_BUILD_SHARED_LIBS=ON -DSD_BUILD_SHARED_GGML_LIB=ON -DGGML_BACKEND_DL=ON -DGGML_CPU_ALL_VARIANTS=ON"},{"build":"cuda12","defines":"-DSD_CUDA=ON -DSD_BUILD_SHARED_LIBS=ON -DCMAKE_CUDA_ARCHITECTURES=''61;70;75;80;86;89;90;100;120'' -DCMAKE_CUDA_FLAGS=''-Xcudafe \"--diag_suppress=177\" -Xcudafe \"--diag_suppress=550\"'' -DGGML_NATIVE=OFF -DSD_BUILD_SHARED_GGML_LIB=ON -DGGML_BACKEND_DL=ON -DGGML_CPU_ALL_VARIANTS=ON"},{"build":"vulkan","defines":"-DSD_VULKAN=ON -DSD_BUILD_SHARED_LIBS=ON -DGGML_NATIVE=OFF -DSD_BUILD_SHARED_GGML_LIB=ON -DGGML_BACKEND_DL=ON -DGGML_CPU_ALL_VARIANTS=ON"}]') || fromJSON('[{"build":"cpu","defines":"-DGGML_NATIVE=OFF -DSD_BUILD_SHARED_LIBS=ON -DSD_BUILD_SHARED_GGML_LIB=ON -DGGML_BACKEND_DL=ON -DGGML_CPU_ALL_VARIANTS=ON"}]') }}
+
     steps:
       - name: Clone
         id: checkout
@@ -446,6 +444,7 @@ jobs:
             sd-${{ env.BRANCH_NAME }}-${{ steps.commit.outputs.short }}-bin-win-${{ matrix.build }}-x64.zip
 
   windows-latest-rocm:
+    if: ${{ github.event_name == 'workflow_dispatch' }}
     runs-on: windows-2022
 
     env:
@@ -572,6 +571,7 @@ jobs:
             sd-${{ env.BRANCH_NAME }}-${{ steps.commit.outputs.short }}-bin-win-rocm-${{ env.ROCM_VERSION }}-x64.zip
 
   ubuntu-latest-rocm:
+    if: ${{ github.event_name == 'workflow_dispatch' }}
     runs-on: ubuntu-24.04
 
     env: