EnvoyFilter is not applied when rediness gate exists and health check failed in Istio

Config
1

We have an EnvoyFilter for route http request to upstream application port as below:

apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
  name: my-envoy-filter
spec:
  workloadSelector:
    labels:
      app: my-app
  configPatches:
  - applyTo: ROUTE_CONFIGURATION
    match:
      context: SIDECAR_INBOUND
      routeConfiguration:
        portNumber: 80
        vhost:
          name: "inbound|http|80"
    patch:
      operation: MERGE
      value:
       name: local_route
       virtual_hosts:
        - name: local_service
          domains:
            - "*.myservice.com"
          routes:
            - match: { prefix: "/" }
              route:
                cluster: mycluster
                priority: HIGH
  - applyTo: CLUSTER
    match:
      context: SIDECAR_INBOUND
    patch:
      operation: ADD
      value:
        name: mycluster
        type: LOGICAL_DNS
        connect_timeout: 0.25s
        lb_policy: ROUND_ROBIN
        load_assignment:
          cluster_name: mycluster
          endpoints:
            - lb_endpoints:
              - endpoint:
                  address:
                    socket_address:
                      address: 127.0.0.1
                      port_value: 9999

It works properly when I applied it to workloads which doesn’t have any rediness gate property (for associated AWS target group).

However, if a workload has its own rediness gate and the rediness check failed, then the EnvoyFilter doesn’t seem to be applied properly.

Is it an intended result?
Are the proxy configurations are applied after the rediness gate confirmed the health of the proxy?
Is there anyway to apply proxy configurations such as EnvoyFilter before the rediness gate confirmation?