Limiting resources watched by Istio Control Plane

I have a use case where I need a way to restrict the set of resources (services/endpoints/pods) that the Istio control plane watches (for the purpose of improving performance). I would like to be able to select the resources based on labels. I’ve looked into discoverySelectors (Istioldie 1.9 / Use discovery selectors to configure namespaces for your Istio service mesh). I would basically like to do something similar. I would like Istio to watch all namespaces (so discoverySelectors doesn’t help here), but restrict it to services/endpoints/pods with specific labels.

I’ve searched around and can’t find anything online to accomplish this. I am wondering if there is a configuration to do this?

Thanks in advance for any suggestions!