I feel like the best way to handle the situation with similar/same communities on different instances is to allow communities to automatically federated with other communities. That way subscribing to one community will show you its posts and all the posts to its linked communities.

It would be especially helpful for these general purpose communities like Technology or News since I would imagine most communities are going to have one.

If that happens then we wouldn’t need to hunt down and follow every single instance of the same community. Let the mods handle it on their end to save the rest of us the effort.