Sadly limiting instances like mastodon can do isn't available in lemmy or kbin afaik, so highly moderated instances like beehaw are resorting to complete disconnection (defederation) for now until moderation tooling improves.

One caveat about the current implementations is that a defederated instance doesn't seem to know it's been defederated from, so a stale copy of the remote content still exists and can be interacted with (users can post in the remote community that defederated and comment on stale posts, or even new posts in the remote community that are made by local users, however none of that will get synced to the remote communities / instance that defederated).