Sourcehut needs a graphical history view (akin to gitk or git log --graph; not sure what the mercurial equivalent is, definitely NOT ANYTHING LIKE that "network graph" github has) to be feature complete. I'd contribute but I have more free money than free time; is there some kind of bounty program?
There's no bounty program (or way to financially incentivise particular features at all, really), but since it's an open-source project and accepts third-party patches, you could consider hiring any freelancer to put in the work. Send them to #sr.ht on irc.freenode.net and I'll show them the ropes.