diff --git a/.github/workflows/scripts-android.yml b/.github/workflows/scripts-android.yml
index 9a7988ed29..097f422a7d 100644
--- a/.github/workflows/scripts-android.yml
+++ b/.github/workflows/scripts-android.yml
@@ -72,6 +72,19 @@ name: Test Android build scripts
 
 jobs:
   build-android:
+    name: Build Android ${{ matrix.name }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: "Default: 8"
+            id: default
+          - name: "JDK 17"
+            id: jdk17
+            java_version: '17'
+          - name: "JDK 21"
+            id: jdk21
+            java_version: '21'
     permissions:
       contents: read
       pull-requests: write
@@ -82,6 +95,28 @@ jobs:
       GH_TOKEN: ${{ secrets.CN1SS_GH_TOKEN }}
     steps:
       - uses: actions/checkout@v4
+      - name: Free Disk Space
+        if: matrix.id != 'default'
+        run: |
+          sudo rm -rf /usr/share/dotnet
+          sudo rm -rf /usr/local/lib/android/sdk/ndk
+          sudo rm -rf /opt/ghc
+          sudo rm -rf /usr/share/swift
+      - name: Setup JDK
+        if: matrix.id != 'default'
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ matrix.java_version }}
+          distribution: 'zulu'
+      - name: Set JDK_HOME
+        if: matrix.id != 'default'
+        run: echo "JDK_HOME=${JAVA_HOME}" >> $GITHUB_ENV
+      - name: Configure CN1SS options
+        if: matrix.id != 'default'
+        run: |
+          echo "CN1SS_SKIP_COMMENT=1" >> $GITHUB_ENV
+          echo "CN1SS_FAIL_ON_MISMATCH=1" >> $GITHUB_ENV
+          echo "CN1SS_SKIP_COVERAGE=1" >> $GITHUB_ENV
       - name: Setup workspace
         run: ./scripts/setup-workspace.sh -q -DskipTests
       - name: Build Android port
@@ -100,11 +135,9 @@ jobs:
           api-level: 31
           arch: x86_64
           target: google_apis
-          script: |
-            ./scripts/run-android-instrumentation-tests.sh "${{ steps.build-android-app.outputs.gradle_project_dir }}"
-            ./scripts/generate-android-coverage-report.sh "${{ steps.build-android-app.outputs.gradle_project_dir }}"
+          script: ./scripts/run-android-instrumentation-tests.sh "${{ steps.build-android-app.outputs.gradle_project_dir }}"
       - name: Upload emulator screenshot
-        if: always()   # still collect it if tests fail
+        if: always() && matrix.id == 'default'
         uses: actions/upload-artifact@v4
         with:
           name: emulator-screenshot
@@ -113,7 +146,7 @@ jobs:
           retention-days: 14
           compression-level: 6
       - name: Upload Android Jacoco coverage report
-        if: always()
+        if: always() && matrix.id == 'default'
         uses: actions/upload-artifact@v4
         with:
           name: android-jacoco-coverage
diff --git a/scripts/android/screenshots/GraphicsPipeline.png b/scripts/android/screenshots/GraphicsPipeline.png
deleted file mode 100644
index 9e8cc9736c..0000000000
Binary files a/scripts/android/screenshots/GraphicsPipeline.png and /dev/null differ
diff --git a/scripts/android/screenshots/GraphicsShapesAndGradients.png b/scripts/android/screenshots/GraphicsShapesAndGradients.png
deleted file mode 100644
index 7d9eb277a4..0000000000
Binary files a/scripts/android/screenshots/GraphicsShapesAndGradients.png and /dev/null differ
diff --git a/scripts/android/screenshots/GraphicsStateAndText.png b/scripts/android/screenshots/GraphicsStateAndText.png
deleted file mode 100644
index 248055fb78..0000000000
Binary files a/scripts/android/screenshots/GraphicsStateAndText.png and /dev/null differ
diff --git a/scripts/android/screenshots/GraphicsTransformations.png b/scripts/android/screenshots/GraphicsTransformations.png
deleted file mode 100644
index f7003a4a9b..0000000000
Binary files a/scripts/android/screenshots/GraphicsTransformations.png and /dev/null differ
diff --git a/scripts/android/screenshots/graphics-draw-line.png b/scripts/android/screenshots/graphics-draw-line.png
index 87456224e0..f4534df057 100644
Binary files a/scripts/android/screenshots/graphics-draw-line.png and b/scripts/android/screenshots/graphics-draw-line.png differ
diff --git a/scripts/android/screenshots/graphics-draw-string-decorated.png b/scripts/android/screenshots/graphics-draw-string-decorated.png
index dcfa054a4e..2c7f16af45 100644
Binary files a/scripts/android/screenshots/graphics-draw-string-decorated.png and b/scripts/android/screenshots/graphics-draw-string-decorated.png differ
diff --git a/scripts/android/screenshots/graphics-draw-string.png b/scripts/android/screenshots/graphics-draw-string.png
index edd1d22eb0..5f87858b18 100644
Binary files a/scripts/android/screenshots/graphics-draw-string.png and b/scripts/android/screenshots/graphics-draw-string.png differ
diff --git a/scripts/android/screenshots/kotlin.png b/scripts/android/screenshots/kotlin.png
index 7434c090bb..5c03ec4f70 100644
Binary files a/scripts/android/screenshots/kotlin.png and b/scripts/android/screenshots/kotlin.png differ
diff --git a/scripts/build-android-app.sh b/scripts/build-android-app.sh
index 4fb840aa9b..6d90a33c53 100755
--- a/scripts/build-android-app.sh
+++ b/scripts/build-android-app.sh
@@ -131,9 +131,9 @@ if [ ! -f "$PATCH_GRADLE_SOURCE_PATH/$PATCH_GRADLE_MAIN_CLASS.java" ]; then
   exit 1
 fi
 
-PATCH_GRADLE_JAVA="${JAVA17_HOME}/bin/java"
+PATCH_GRADLE_JAVA="${JDK_HOME:-$JAVA17_HOME}/bin/java"
 if [ ! -x "$PATCH_GRADLE_JAVA" ]; then
-  ba_log "JDK 17 java binary missing at $PATCH_GRADLE_JAVA" >&2
+  ba_log "JDK java binary missing at $PATCH_GRADLE_JAVA" >&2
   exit 1
 fi
 
@@ -151,7 +151,7 @@ echo "---------------------------------"
 ba_log "Invoking Gradle build in $GRADLE_PROJECT_DIR"
 chmod +x "$GRADLE_PROJECT_DIR/gradlew"
 ORIGINAL_JAVA_HOME="$JAVA_HOME"
-export JAVA_HOME="$JAVA17_HOME"
+export JAVA_HOME="${JDK_HOME:-$JAVA17_HOME}"
 (
   cd "$GRADLE_PROJECT_DIR"
   if command -v sdkmanager >/dev/null 2>&1; then
diff --git a/scripts/lib/cn1ss.sh b/scripts/lib/cn1ss.sh
index 38ae8fbac5..e054bd16dc 100644
--- a/scripts/lib/cn1ss.sh
+++ b/scripts/lib/cn1ss.sh
@@ -403,9 +403,18 @@ cn1ss_process_and_report() {
 
   cn1ss_log "STAGE:COMMENT_POST -> Submitting PR feedback"
   local comment_rc=0
-  if ! cn1ss_post_pr_comment "$comment_out" "$preview_dir"; then
+  if [ "${CN1SS_SKIP_COMMENT:-0}" = "1" ]; then
+    cn1ss_log "Skipping PR comment as requested (CN1SS_SKIP_COMMENT=1)"
+  elif ! cn1ss_post_pr_comment "$comment_out" "$preview_dir"; then
     comment_rc=$?
   fi
 
+  if [ "${CN1SS_FAIL_ON_MISMATCH:-0}" = "1" ]; then
+    if [ -f "$summary_out" ] && (grep -q "^different|" "$summary_out" || grep -q "^error|" "$summary_out"); then
+      cn1ss_log "FATAL: Screenshot mismatches or errors detected (CN1SS_FAIL_ON_MISMATCH=1)"
+      return 15
+    fi
+  fi
+
   return $comment_rc
 }
diff --git a/scripts/run-android-instrumentation-tests.sh b/scripts/run-android-instrumentation-tests.sh
index 18811f0c42..06c6381d2e 100755
--- a/scripts/run-android-instrumentation-tests.sh
+++ b/scripts/run-android-instrumentation-tests.sh
@@ -56,13 +56,15 @@ if [ -z "${JAVA17_HOME:-}" ]; then
   exit 3
 fi
 
-JAVA17_BIN="$JAVA17_HOME/bin/java"
-if [ ! -x "$JAVA17_BIN" ]; then
-  ra_log "JDK 17 java binary missing at $JAVA17_BIN" >&2
+TARGET_JAVA_HOME="${JDK_HOME:-$JAVA17_HOME}"
+TARGET_JAVA_BIN="$TARGET_JAVA_HOME/bin/java"
+
+if [ ! -x "$TARGET_JAVA_BIN" ]; then
+  ra_log "Target java binary missing at $TARGET_JAVA_BIN" >&2
   exit 3
 fi
 
-cn1ss_setup "$JAVA17_BIN" "$CN1SS_HELPER_SOURCE_DIR"
+cn1ss_setup "$TARGET_JAVA_BIN" "$CN1SS_HELPER_SOURCE_DIR"
 
 [ -d "$GRADLE_PROJECT_DIR" ] || { ra_log "Gradle project directory not found: $GRADLE_PROJECT_DIR"; exit 4; }
 [ -x "$GRADLE_PROJECT_DIR/gradlew" ] || chmod +x "$GRADLE_PROJECT_DIR/gradlew"
@@ -115,7 +117,7 @@ GRADLE_CMD=("$GRADLEW" --stacktrace --info --no-daemon connectedDebugAndroidTest
 ra_log "Executing connectedDebugAndroidTest via Gradle"
 if ! (
   cd "scripts/hellocodenameone/android/target/hellocodenameone-android-1.0-SNAPSHOT-android-source"
-  JAVA_HOME="$JAVA17_HOME" "${GRADLE_CMD[@]}"
+  JAVA_HOME="${JDK_HOME:-$JAVA17_HOME}" "${GRADLE_CMD[@]}"
 ); then
   ra_log "FATAL: connectedDebugAndroidTest failed"
   exit 10
@@ -140,15 +142,19 @@ done
 
 sleep 3
 
-ra_log "STAGE:COVERAGE -> Collecting Jacoco coverage report"
-if ARTIFACTS_DIR="$ARTIFACTS_DIR" "$SCRIPT_DIR/generate-android-coverage-report.sh" "$GRADLE_PROJECT_DIR"; then
-  if [ -f "$COVERAGE_SUMMARY" ]; then
-    ra_log "  -> Coverage summary detected at $COVERAGE_SUMMARY"
+if [ "${CN1SS_SKIP_COVERAGE:-0}" = "1" ]; then
+  ra_log "Skipping coverage report generation (CN1SS_SKIP_COVERAGE=1)"
+else
+  ra_log "STAGE:COVERAGE -> Collecting Jacoco coverage report"
+  if ARTIFACTS_DIR="$ARTIFACTS_DIR" "$SCRIPT_DIR/generate-android-coverage-report.sh" "$GRADLE_PROJECT_DIR"; then
+    if [ -f "$COVERAGE_SUMMARY" ]; then
+      ra_log "  -> Coverage summary detected at $COVERAGE_SUMMARY"
+    else
+      ra_log "  -> Coverage summary not found after report generation"
+    fi
   else
-    ra_log "  -> Coverage summary not found after report generation"
+    ra_log "WARNING: Coverage report generation failed; continuing without coverage details"
   fi
-else
-  ra_log "WARNING: Coverage report generation failed; continuing without coverage details"
 fi
 
 declare -a CN1SS_SOURCES=("LOGCAT:$TEST_LOG")