What I think would be better would be adding tagging and taking federation a step further. Every post needs a ‘tag’; we steal that part from mastadon. It can have many, but it needs at least one, say #politics in this example.

Tags also bring issues from a moderation perspective. Who can decide who can use tags to label which type content? Seems another way to have everyone spamming trending tags on all type of contents without control. I think tags work better on a microblog format than community format, where you can potentially reach out everyone following that community/tag much easily than crossposting each time.

As far as an abuse vector. Thats just hang wringing. IF your mods are that abusive for a large sub, you’ve got way bigger issues. Which, if it did ever happen, is something that “forking” would solve. Mod on a power trip? No problem. Fork the community.

I was more thinking about people wanting to ruin things by importing huge communities to small instances, consuming their space and resources, and making it confusing to people to know which one is the "legit" community.

And if you limit this feature to admins, then requesting communities is already possible from admins on most of the instances, so that covers the transfer. Fork/split (what is the difference, btw), as I said, can be done manually now.

Importing a community is the one use case remaining, but I see why it's not a priority for the Lemmy devs, there is bigger fish to fry at the moment (multicommunities for instance)