This is an issue I've been wondering about, the Technology example is fine, but the real edge case IMO is Official Communities.
Like, let's say I have an Android App and want to migrate my official community to Lemmy. I could build a community in:
- A big and general instance to gather more users, like Lemmy.World.
- A big but themed instance, like Lemdro.id. It has a smaller number of users but they are more likely to be interested in my App
- I could make my own instance, which would allow me to dedicate communities into topics and I would have more control over it, which is good cause it is an official community.
I feel there should be a way for "sync" communities in those cases. It makes sense in those cases to allow a full sync, with the option to unsync if things go south and there's a split.