I would encourage every Fediverse software project to implement a “dead-man switch" on registrations: if nobody with moderator permissions has been active in the last week, then disable new account creation.

The Fediverse has a significant number of abandoned instances that are used by bad actors to create accounts and send spam.

We implemented this in Mastodon (https://github.com/mastodon/mastodon/pull/29318) and it has been highly effective.