Huh yeah I've never even looked into that,but you raise a good point. I personally don't love working on android apps, only do if there's something I want that hasn't been done yet.
As mull appears to have the lowest number of bits of identifying information exposed in my tests of different android browsers on the eff's website, I'm willing to try to maintain until someone more experienced comes around. But looking at the repo it doesn't seem super involved but I won't really have a good idea until I actually get to trying
I'll prob get downvoted for this, but paste the instructions into an LLM and have it assist you. misread OP's comment
As for user.js prefs potentially aging out, arkenfox updates very rarely (once every few months IIRC), so the present user.js should be fine for a while until someone inevitably forks and maintains mull.
Personally I had to change mulls prefs('<...>') to user_prefs or vice versa to get it to work.