diff --git a/.github/workflows/ci-external-config.yaml b/.github/workflows/ci-external-config.yaml
index a0072e49..7fcf9af4 100644
--- a/.github/workflows/ci-external-config.yaml
+++ b/.github/workflows/ci-external-config.yaml
@@ -34,7 +34,7 @@ jobs:
           helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
           helm repo update
           kubectl create namespace monitoring
-          helm install prometheus-operator prometheus-community/kube-prometheus-stack --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
+          helm install prometheus-operator prometheus-community/kube-prometheus-stack --version 89.2.4 --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
 
       - name: Install KEDA Autoscaler
         run: |
diff --git a/.github/workflows/ci-full.yaml b/.github/workflows/ci-full.yaml
index 9416fc7d..6811db2a 100644
--- a/.github/workflows/ci-full.yaml
+++ b/.github/workflows/ci-full.yaml
@@ -34,7 +34,7 @@ jobs:
           helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
           helm repo update
           kubectl create namespace monitoring
-          helm install prometheus-operator prometheus-community/kube-prometheus-stack --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
+          helm install prometheus-operator prometheus-community/kube-prometheus-stack --version 89.2.4 --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
 
       - name: Install KEDA Autoscaler
         run: |
diff --git a/.github/workflows/ci-local.sh b/.github/workflows/ci-local.sh
index 7f255758..6bc72588 100644
--- a/.github/workflows/ci-local.sh
+++ b/.github/workflows/ci-local.sh
@@ -53,6 +53,7 @@ helm repo add prometheus-community https://prometheus-community.github.io/helm-c
 helm repo update
 kubectl create namespace monitoring
 helm install prometheus-operator prometheus-community/kube-prometheus-stack \
+  --version 89.2.4 \
   --namespace monitoring \
   --set prometheusOperator.createCustomResource=false \
   --set defaultRules.create=false \
diff --git a/README.md b/README.md
index 45a9fe60..6d77631c 100644
--- a/README.md
+++ b/README.md
@@ -55,7 +55,7 @@ Currently, SuperSONIC supports the following functionality:
     helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
     helm repo update
     kubectl create namespace monitoring
-    helm install prometheus-operator prometheus-community/kube-prometheus-stack --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
+    helm install prometheus-operator prometheus-community/kube-prometheus-stack --version 89.2.4 --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
     ```
     </details>
   - [KEDA](https://keda.sh) CRDs (only if using autoscaling)
diff --git a/docs/configuration-guide.rst b/docs/configuration-guide.rst
index 8fe2d7fe..2b3e40b3 100644
--- a/docs/configuration-guide.rst
+++ b/docs/configuration-guide.rst
@@ -163,10 +163,10 @@ default configuration completely (the configuration file must be supplied as a C
        configmap_name: external-envoy-config
        configmap_key: envoy.yaml
 
-.. warning::
-
-   ``scaleFromZero.enabled`` cannot be used with ``envoy.external_config.load_from_configmap``.
-   Scale-from-zero injects Envoy clusters and a Lua filter that an external ConfigMap would replace.
+``scaleFromZero`` and the prometheus-based rate limiter work with an external
+configuration only if it carries the clusters, Lua filter and routes that the generated
+configuration would have added (see ``templates/envoy/configmaps.yaml``); the chart does
+not check for them.
 
 5. (Optional) Configure Rate Limiting in Envoy Proxy
 ======================================================
@@ -408,7 +408,7 @@ count. Helm upgrades keep the live ScaledObject ``minReplicaCount`` so they do n
 interrupt an active hold. The hold deadline is stored as an annotation on the
 ScaledObject, so the admission sidecars of multiple Envoy replicas share one hold
 and none can release a peer's active hold. ``scaleFromZero`` requires ``keda.enabled`` and
-``envoy.enabled``, and cannot be used with an external Envoy ConfigMap.
+``envoy.enabled``.
 
 Do not set ``keda.zeroIdleReplicas: true`` together with ``minReplicaCount: 0``.
 ``zeroIdleReplicas`` sets KEDA ``idleReplicaCount`` to 0 and cannot scale from 0 back to 1
diff --git a/helm/supersonic/README.md b/helm/supersonic/README.md
index 45a9fe60..6d77631c 100644
--- a/helm/supersonic/README.md
+++ b/helm/supersonic/README.md
@@ -55,7 +55,7 @@ Currently, SuperSONIC supports the following functionality:
     helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
     helm repo update
     kubectl create namespace monitoring
-    helm install prometheus-operator prometheus-community/kube-prometheus-stack --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
+    helm install prometheus-operator prometheus-community/kube-prometheus-stack --version 89.2.4 --namespace monitoring --set prometheusOperator.createCustomResource=false --set defaultRules.create=false --set alertmanager.enabled=false --set prometheus.enabled=false --set grafana.enabled=false
     ```
     </details>
   - [KEDA](https://keda.sh) CRDs (only if using autoscaling)
diff --git a/helm/supersonic/templates/envoy/admission.yaml b/helm/supersonic/templates/envoy/admission.yaml
index 03b7860b..bfdf5d39 100644
--- a/helm/supersonic/templates/envoy/admission.yaml
+++ b/helm/supersonic/templates/envoy/admission.yaml
@@ -5,9 +5,6 @@
 {{- if not .Values.envoy.enabled }}
 {{- fail "scaleFromZero.enabled requires envoy.enabled" }}
 {{- end }}
-{{- if .Values.envoy.external_config.load_from_configmap }}
-{{- fail "scaleFromZero.enabled is incompatible with envoy.external_config.load_from_configmap" }}
-{{- end }}
 apiVersion: v1
 kind: ServiceAccount
 metadata:
diff --git a/helm/supersonic/templates/envoy/configmaps.yaml b/helm/supersonic/templates/envoy/configmaps.yaml
index fa74e4fb..7b14cd79 100644
--- a/helm/supersonic/templates/envoy/configmaps.yaml
+++ b/helm/supersonic/templates/envoy/configmaps.yaml
@@ -303,7 +303,7 @@ data:
 {{- end }}
 ---
 
-{{- if and (include "supersonic.luaFilterEnabled" .) (not .Values.envoy.external_config.load_from_configmap) }}
+{{- if (include "supersonic.luaFilterEnabled" .) }}
 {{- /* Create a ConfigMap for the Lua filter */}}
 apiVersion: v1
 kind: ConfigMap