OC What's the best way to federate magazines/communities from a UI perspective?

Been rolling this over in my head for a bit, and am curious what makes sense to other folks.

From a user side, they can choose to add magazines/communities from any instance to a group that they define and give a nickname. This gives an individual user the only say in deciding what magazines should show up in the same place.

Any automated way of doing this is going to be hard and have edge cases, I think this is a small amount to ask and people could share collections from different instances to bootstrap. But if someone really hates the vibe of a particular instance's version of a topic (or doesn't think it's moderated to their liking) they can disconnect from it with one button.

On the posting side, it makes sense that the user would need to select one particular instance to make their "primary" for the purposes of posting.

The mods from the primary instance would be responsible for their posts; the mixing of posts from different instances would be entirely defined by the user so there's no need to think about cross-instance moderation.

The result is that you're able to follow things in a way that is convenient for you, but there's no guarantee that someone else will necessarily see your post unless they follow your primary instance.

That seems like the right balance to me, to make virtual communities large enough to be useful without forcing everyone to join the biggest instance.