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.
I saw the writing on the wall a few years back, it was so painfully obvious. I started switching to KiCAD early, and feel so bad for ever recommending Eagle to people who will now have to learn yet another new tool in order to find something usable.
Fusion360 is so bad, I had to explain why SolidWorks was different earlier today and they were shocked by things like "if I move the case the board I say is attached to the case moves to" and "I don't have to align it by eye, it's a computer".
And I'm definitely not starting VMWare to run Fusion360 with nonsense online components that slow it down to uselessness and integrate it into a tool that doesn't need to be on at all... it's just not possible. It was obvious once they stopped updating the version. It's pathetic nonetheless that they cannot think beyond the one-true-way of integrating a dozen mediocre tools into one extra-mediocre product.