diff --git a/OneBranchPipelines/stages/build-linux-single-stage.yml b/OneBranchPipelines/stages/build-linux-single-stage.yml
index 06565f34b..e50123769 100644
--- a/OneBranchPipelines/stages/build-linux-single-stage.yml
+++ b/OneBranchPipelines/stages/build-linux-single-stage.yml
@@ -48,8 +48,8 @@ stages:
           name: Python-1ES-pool
           demands:
           - imageOverride -equals PYTHON-1ES-UB2404
-        # Extended timeout for multi-version builds + testing (5 Python versions × build + test time)
-        timeoutInMinutes: 120
+        # Six serial build/test cycles exceed two hours under QEMU-based ARM64 emulation.
+        timeoutInMinutes: 180
         
         variables:
           # Disable BinSkim for Linux - requires ICU libraries not available in manylinux/musllinux containers
@@ -433,6 +433,8 @@ stages:
                   '
                 fi
                 
+                # Avoid accumulating six copies of the test tree on emulated ARM64 jobs.
+                docker exec build-$(LINUX_TAG)-$(ARCH) $SHELL_EXE -lc "rm -rf /test_isolated_${PYBIN}"
                 echo "✓ Build and test complete for $PYBIN"
               done
               
@@ -448,7 +450,7 @@ stages:
           - script: |
               set -euo pipefail
               
-              # Copy all wheels (5 Python versions) to output directory
+              # Copy all wheels (6 Python versions) to output directory
               echo "Copying wheels to host..."
               docker cp build-$(LINUX_TAG)-$(ARCH):/workspace/dist/. "$(ob_outputDirectory)/wheels/" || echo "No wheels found"
               
diff --git a/OneBranchPipelines/stages/build-macos-single-stage.yml b/OneBranchPipelines/stages/build-macos-single-stage.yml
index 9d94245f5..65909d55b 100644
--- a/OneBranchPipelines/stages/build-macos-single-stage.yml
+++ b/OneBranchPipelines/stages/build-macos-single-stage.yml
@@ -91,13 +91,13 @@ stages:
           # =========================
           # BUILD TOOLS
           # =========================
-          # CMake = cross-platform build system generator (needed for C++ compilation)
-          # Uninstall first to ensure clean version (avoid conflicts with pre-installed CMake)
+          # Install all Homebrew tooling in one transaction, matching PR validation.
+          # Do not run brew update: hosted runners already provide bottle metadata,
+          # while updating can select formulae that compile Go and Lima from source.
           - script: |
-              brew update
               brew uninstall cmake --ignore-dependencies || echo "CMake not installed"
-              brew install cmake
-            displayName: 'Install CMake'
+              brew install cmake docker colima
+            displayName: 'Install build & container tooling (Homebrew)'
           
           # =========================
           # PYTHON DEPENDENCIES
@@ -133,22 +133,15 @@ stages:
               TargetFolder: '$(ob_outputDirectory)/bindings/macOS'
             displayName: 'Copy .so files'
           
-          # Install Docker CLI and Colima (macOS Docker runtime)
+          # Start Colima (macOS Docker runtime). Tooling is installed above so the
+          # 15-minute timeout covers only VM startup, not Homebrew compilation.
           # Colima = lightweight Docker Desktop alternative using macOS virtualization
-          # vz = native macOS virtualization (faster, only works on M1+)
-          # qemu = cross-platform emulator (slower, works on Intel Macs)
           # 4 CPU cores + 8GB RAM needed for SQL Server container
           - script: |
-              brew update
-              brew install docker colima
-              colima start --vm-type vz --cpu 4 --memory 8 || {
-                echo "vz VM failed, trying qemu..."
-                colima start --vm-type qemu --cpu 4 --memory 8
-              }
-              sleep 30
+              colima start --cpu 4 --memory 8 --disk 50
               docker context use colima >/dev/null || true
               docker version
-            displayName: 'Install and start Docker (Colima)'
+            displayName: 'Start Docker (Colima)'
             timeoutInMinutes: 15
           
           # =========================