Or even simpler, a feature that lets you aggregate history, posts, comments and subscriptions from multiple instances in a transparent way.
Sort of a meta-account / fedacount that tells all Lemmy instances that accounts a, b, c, and d are all the same user.
I see a lot of folks referencing topology, but clearly topology is not a particularly good go-to for how to talk about holes.
From a topological perspective, a hole in the ground isn’t a hole… But you can still fall into it.
From a topological perspective, a hole in your logic isn’t a hole – but you can still have one.
Clearly we’re talking linguistically, not topologically.