I think you can use the remindme bot on mastodon, although I’ll have to check the syntax. Saw someone use it in another thread
I also like the smaller communities in some cases. It’s a lot easier to participate and have replies to your questions/comments.
For a few communities though they’re still too small to be sustainable and useful. Need more time for those ones. Say LegalAdvice, communities for sales / discounts, or local ones for schools and cities.