@kev I think what scares many sysadms. like me from opening instance open for registration, is the work associated with moderation, takedown requests and such nontechnical work.
I think more federation could helped by making it really easy install a "family" #mastodon server, maybe as a app on #Nextcloud or as a #docker instance. Moderating a small instance with only your friends and family seems more manageable job.
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.