diff --git a/.github/actions/constellation_create/action.yml b/.github/actions/constellation_create/action.yml
index 67d84e550..b02d31add 100644
--- a/.github/actions/constellation_create/action.yml
+++ b/.github/actions/constellation_create/action.yml
@@ -67,6 +67,9 @@ outputs:
   masterSecret:
     description: "The master-secret for the cluster."
     value: ${{ steps.constellation-init.outputs.MASTERSECRET }}
+  osImageUsed:
+    description: "The OS image used in the cluster."
+    value: ${{ steps.setImage.outputs.image }}
 
 runs:
   using: "composite"
@@ -132,11 +135,20 @@ runs:
           constellation-conf.yaml
 
     - name: Set image
-      if: inputs.osImage != ''
+      id: setImage
       shell: bash
       env:
-        image: ${{ inputs.osImage }}
-      run: yq eval -i "(.image) = \"${image}\"" constellation-conf.yaml
+        imageInput: ${{ inputs.osImage }}
+      run: |
+        if [[ -z "${imageInput}" ]]; then
+          echo "No image specified. Using default image from config."
+          image=$(yq eval ".image" constellation-conf.yaml)
+          echo "image=${image}" | tee -a "$GITHUB_OUTPUT"
+          exit 0
+        fi
+
+        yq eval -i "(.image) = \"${imageInput}\"" constellation-conf.yaml
+        echo "image=${imageInput}" | tee -a "$GITHUB_OUTPUT"
 
     - name: Set instanceType
       if: inputs.machineType && inputs.machineType != 'default'
diff --git a/.github/actions/e2e_test/action.yml b/.github/actions/e2e_test/action.yml
index a5c0ba2c7..3959dcd7f 100644
--- a/.github/actions/e2e_test/action.yml
+++ b/.github/actions/e2e_test/action.yml
@@ -260,7 +260,7 @@ runs:
       uses: ./.github/actions/e2e_verify
       with:
         cloudProvider: ${{ inputs.cloudProvider }}
-        osImage: ${{ inputs.osImage }}
+        osImage: ${{ steps.constellation-create.outputs.osImageUsed }}
 
     - name: Run recover test
       if: inputs.test == 'recover'
diff --git a/.github/workflows/e2e-test-release.yml b/.github/workflows/e2e-test-release.yml
index 9dfc6a2a8..9ed7455a8 100644
--- a/.github/workflows/e2e-test-release.yml
+++ b/.github/workflows/e2e-test-release.yml
@@ -35,7 +35,7 @@ jobs:
   e2e-tests:
     strategy:
       fail-fast: false
-      max-parallel: 4
+      max-parallel: 9
       matrix:
         test:
           [
@@ -208,12 +208,11 @@ jobs:
 
   e2e-upgrade:
     strategy:
-        fail-fast: false
-        max-parallel: 1
-        matrix:
-          fromVersion:
-            ["v2.6.0"]
-          cloudProvider: ["gcp", "azure"]
+      fail-fast: false
+      max-parallel: 1
+      matrix:
+        fromVersion: ["v2.6.0"]
+        cloudProvider: ["gcp", "azure"]
     name: Run upgrade tests
     secrets: inherit
     permissions: