How to specify registry mirror settings

we have a use case of providing some images from a private repo, we can pull them via specifying the secret and pod pull them but multiple pods end up pulling them,
How can we add details to the registry to run it as a registry mirror so that it can cache those images?
something mentioned here

Or import custom images after installation

I don’t believe registry mirror is able to replicate any private registry. As the docs mention, it only works with the central Docker Hub:

It’s currently not possible to mirror another private registry. Only the central Hub can be mirrored.

Is it possible for you to bundle these images in the cluster image you build during tele build? This way they will be automatically replicated across all in-cluster registries.

All images pushed to the in-cluster registries “out-of-band” are not managed by Gravity and as such they won’t be replicated and may be removed during garbage collection operation.