Provide a mechanism in the managed kubernetes UI to download a kubeconfig that has tokens and config for ALL clusters, but configured with contexts for all clusters to allow readily switching between them.

RIght now, you create a config that has a 'default' context, and a context for the single cluster.

If token is compatible between clusters, then a single 'user' definition would work - otherwise user definition would probably need to exist for each cluster in the configuration.