[Question] AKS Istio add-on - Registry url for sidecar container

**Describe scenario**
I am using the AKS Istio add-on (managed Istio) for a project. Project namespaces have a policy that only allows container images to be pulled only from an internal/private registry and not MCR (`mcr.microsoft.com`).

**Question**
Is there a supported way to configure a custom container registry URL for the Istio sidecar proxy injected by the AKS Istio add-on?
For example, in self-managed Istio this is possible via `global.hub` in the `IstioOperator` spec, but since the add-on manages the `MutatingWebhookConfiguration` and sidecar injector, it's unclear if this can be overridden. If not currently supported, is this on the roadmap?

PS: I know that [AppNet](https://learn.microsoft.com/en-us/azure/application-network/overview) is currently in preview, and I would prefer to use Ambient Mesh instead once it is GA.