Thanks for the suggestion!
Yes, I've thought about something like this but setting communities with inactive moderators to "mod-only" to prevent it from being spammed (and me having to clean it up) instead. They should also be available for "requesting" so other people can take over if they're interested.
I plan on implementing that when I finish the infopage (https://info.ani.social) hopefully by the end of January. I can't attend to it sooner because it's finals season right now and I need to submit a lot of papers (also, I'm sick because of the weather :/).