ha cis multi cluster Openshift route creation

I like to verify that when creating a route on an Openshift multicluster HA cis environment, the endpoints of a service on the secondary cluster are added to the poolmembers automatically.

First I had the annotation below add:

virtual-server.f5.com/multiClusterServices: |
      [
          {
             "clusterName": "openshift-engineering-02",
             "service": "tea-svc",
             "namespace": "cafe",
             "servicePort": 8080,
             "weight": 100
          }
      ]

Creating routes without this annotation still adds the pods of the service with the same name and in the same namespace on the secondary cluster I saw.

Is this annotation not required for a HA cis multi cluster application?

Does HA CIS always add the pods of the secondary cluster as poolmembers if they belong to the same service and namespace as on the primary cluster? And the same if the secondary CIS becomes the active CIS?

What about services on other external clusters? Is the annotation for virtual-server.f5.com/multiClusterServices only required if the service or namespace do not match with the names in the route manifest?