diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index f533a136..af2bda2c 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -140,40 +140,66 @@ jobs:
   check_integration_label:
     runs-on: ubuntu-latest
     needs: [build]
+    permissions:
+      pull-requests: read
     outputs:
       has_geos_integration_label: ${{ steps.set-label.outputs.has_label }}
     steps:
       - name: Check if PR has '${{ env.LABEL_TEST_GEOS_INTEGRATION }}' label
         id: set-label
+        # Fetch labels live from the GitHub REST API rather than reading
+        # github.event.pull_request.labels. The event payload is a snapshot
+        # frozen at the time the workflow was first triggered, so labels
+        # added after that first run are invisible to re-runs.
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+          REQUIRED_LABEL: ${{ env.LABEL_TEST_GEOS_INTEGRATION }}
         run: |
           echo "Checking for label..."
           LABEL_FOUND=false
-          LABELS='${{ toJson(github.event.pull_request.labels.*.name) }}'
+          PR_JSON=$(curl --fail --silent --show-error \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer ${GITHUB_TOKEN}" \
+            "https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}")
+          LABELS=$(echo "${PR_JSON}" | jq -crM '[.labels[].name]')
           echo "PR Labels: $LABELS"
-          if echo "$LABELS" | grep -q "${{ env.LABEL_TEST_GEOS_INTEGRATION }}"; then
+          if echo "$LABELS" | jq -e --arg label "${REQUIRED_LABEL}" 'index($label) != null' > /dev/null; then
             LABEL_FOUND=true
-            echo "Label '${{ env.LABEL_TEST_GEOS_INTEGRATION }}' found"
+            echo "Label '${REQUIRED_LABEL}' found"
           fi
-          echo "has_label=$LABEL_FOUND" >> $GITHUB_OUTPUT
+          echo "has_label=$LABEL_FOUND" >> "$GITHUB_OUTPUT"
 
   check_force_integration_label:
     runs-on: ubuntu-latest
     # needs: [build]
+    permissions:
+      pull-requests: read
     outputs:
       has_geos_integration_force_label: ${{ steps.set-label.outputs.has_label }}
     steps:
       - name: Check if PR has '${{ env.LABEL_FORCE_GEOS_INTEGRATION }}' label
         id: set-label
+        # Fetch labels live from the GitHub REST API rather than reading
+        # github.event.pull_request.labels. The event payload is a snapshot
+        # frozen at the time the workflow was first triggered, so labels
+        # added after that first run are invisible to re-runs.
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+          REQUIRED_LABEL: ${{ env.LABEL_FORCE_GEOS_INTEGRATION }}
         run: |
           echo "Checking for label..."
           LABEL_FOUND=false
-          LABELS='${{ toJson(github.event.pull_request.labels.*.name) }}'
+          PR_JSON=$(curl --fail --silent --show-error \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer ${GITHUB_TOKEN}" \
+            "https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}")
+          LABELS=$(echo "${PR_JSON}" | jq -crM '[.labels[].name]')
           echo "PR Labels: $LABELS"
-          if echo "$LABELS" | grep -q "${{ env.LABEL_FORCE_GEOS_INTEGRATION }}"; then
+          if echo "$LABELS" | jq -e --arg label "${REQUIRED_LABEL}" 'index($label) != null' > /dev/null; then
             LABEL_FOUND=true
-            echo "Label '${{ env.LABEL_FORCE_GEOS_INTEGRATION }}' found"
+            echo "Label '${REQUIRED_LABEL}' found"
           fi
-          echo "has_label=$LABEL_FOUND" >> $GITHUB_OUTPUT
+          echo "has_label=$LABEL_FOUND" >> "$GITHUB_OUTPUT"
 
   # Step 3: Check if GEOS integration is required based on changed files
   check_geos_integration_required:
diff --git a/geos-ats/src/geos/ats/baseline_io.py b/geos-ats/src/geos/ats/baseline_io.py
index 26b1920b..92e3d220 100644
--- a/geos-ats/src/geos/ats/baseline_io.py
+++ b/geos-ats/src/geos/ats/baseline_io.py
@@ -2,6 +2,7 @@
 import logging
 import tempfile
 import shutil
+import subprocess
 import yaml
 import time
 import requests
@@ -161,6 +162,51 @@ def collect_baselines( bucket_name: str,
         raise Exception( f'Could not find baseline files to unpack: expected={archive_name}' )
 
 
+def _available_cpu_count() -> int:
+    if hasattr( os, 'sched_getaffinity' ):
+        return len( os.sched_getaffinity( 0 ) )
+    return os.cpu_count() or 1
+
+
+def _pack_baselines_with_parallel_gzip( archive_name: str, baseline_path: str ) -> bool:
+    tar_bin = shutil.which( 'tar' )
+    pigz_bin = shutil.which( 'pigz' )
+    if not tar_bin or not pigz_bin:
+        logger.info( 'tar and pigz were not both found; using Python gztar archiver' )
+        return False
+
+    archive_path = f'{archive_name}.tar.gz'
+    threads = str( _available_cpu_count() )
+    logger.info( f'Archiving baseline files with tar and pigz -9 ({threads} threads)...' )
+
+    try:
+        with open( archive_path, 'wb' ) as output:
+            tar_process = subprocess.Popen( [ tar_bin, '-C', baseline_path, '-cf', '-', '.' ], stdout=subprocess.PIPE )
+            if tar_process.stdout is None:
+                raise RuntimeError( 'failed to capture tar output' )
+            pigz_process = subprocess.Popen( [ pigz_bin, '-9', '-p', threads ],
+                                             stdin=tar_process.stdout,
+                                             stdout=output )
+            tar_process.stdout.close()
+
+            pigz_status = pigz_process.wait()
+            tar_status = tar_process.wait()
+
+        if tar_status != 0 or pigz_status != 0:
+            try:
+                os.remove( archive_path )
+            except FileNotFoundError:
+                pass
+            raise RuntimeError( f'tar exited with {tar_status}; pigz exited with {pigz_status}' )
+
+    except Exception as e:
+        logger.warning( 'Parallel baseline archive creation failed; using Python gztar archiver' )
+        logger.warning( repr( e ) )
+        return False
+
+    return True
+
+
 def pack_baselines( archive_name: str, baseline_path: str, log_path: str = '' ):
     """
     Pack and upload baselines to GCP
@@ -201,7 +247,8 @@ def pack_baselines( archive_name: str, baseline_path: str, log_path: str = '' ):
 
     try:
         logger.info( 'Archiving baseline files...' )
-        shutil.make_archive( archive_name, format='gztar', root_dir=baseline_path )
+        if not _pack_baselines_with_parallel_gzip( archive_name, baseline_path ):
+            shutil.make_archive( archive_name, format='gztar', root_dir=baseline_path )
         logger.info( f'Created {archive_name}.tar.gz' )
     except Exception as e:
         logger.error( 'Failed to create baseline archive' )
diff --git a/geos-ats/src/geos/ats/helpers/restart_check.py b/geos-ats/src/geos/ats/helpers/restart_check.py
index f4911073..8f44d478 100644
--- a/geos-ats/src/geos/ats/helpers/restart_check.py
+++ b/geos-ats/src/geos/ats/helpers/restart_check.py
@@ -17,7 +17,9 @@
 
 RTOL_DEFAULT = 0.0
 ATOL_DEFAULT = 0.0
-EXCLUDE_DEFAULT = [ ".*/commandLine", ".*/schema$", ".*/globalToLocalMap", ".*/timeHistoryOutput.*/restart" ]
+EXCLUDE_DEFAULT = [
+    ".*/commandLine", ".*/schema$", ".*/globalToLocalMap", ".*/timeHistoryOutput.*/restart", ".*/dNdX", ".*/detJ"
+]
 logger = logging.getLogger( 'geos-ats' )