for context, I would GLADLY move there my Neovim plugin. all it does is brings the current jj message into your editor and lets you integrate it with a status bar (or anything in nvim, really). that would be a decent measure against drive-by slop contributions, and I'd accept contribs over private github mirror from those who I know but can't bother setting up git mail
EDIT: TIL that one can host SourceHut themselves. discoverability may still be a problem (sr.ht just ranks higher in search engines) but 1) fixable with github mirror that points to sourcehut instance as a canonical development platform, 2) it's moderately easy to sync contributions between tangled and sourcehut, so tangled is also an option
EDIT 2: the email part would be PITA, so $4/mo is attractive on that background