The #ForkOffTogether folks could start with a different web client like #Pinafore or #Halcyon, instead of the #Mastodon one. Both of these can use either the Mastodon or #Pleroma back-end. I just logged into Pinafore for the first time, and it was like clouds parting, and a huge weight lifting off my eyeballs (still with the irritating notification noise though).