1) I've just suspended a few dozen spam accounts created in the last 24 hours. How annoying! Registration is now closed, until I come up with a better way of stopping them. Any mathstodon user can invite people to join using the form in the preferences page: https://mathstodon.xyz/invites
2) I've updated the server to Mastodon v2.4.0. Release notes at https://github.com/tootsuite/mastodon/releases/tag/v2.4.0
Some fun features, including four free-text fields you can show on your profile.