ReferenceGrants and ExtensionRef

[mcsrobert]

I had read the docs on ReferenceGrants, and thought they sounded pretty useful and sensible to me, so I tried to make my own:

apiVersion: gateway.networking.k8s.io/v1beta1
kind: ReferenceGrant
metadata:
  name: traefik-middleware-grant
  namespace: traefik
spec:
  from:
    - group: gateway.networking.k8s.io
      kind: HTTPRoute
      namespace: foo
  to:
    - group: traefik.io
      kind: Middleware
      name: auth-chain

I was able to created the ReferenceGrant, only to learn later that the namespace field is not allowed on an ExtensionRef, and thus I don't think they can be used here?

Thought this was a shame and might make sense to support? This would essentially solve traefik/traefik#11126.