Take a look at this comment thread: https://www.reddit.com/r/PleX/comments/17di1vc/comment/k5xkfqd/

It may or may not work for your purposes, seems like mixed results being reported by others. Haven't tried it myself but could be worth a look.

I think FileBot would fit all your criteria.

There is also RestlessOS which explicitly sets out to be a GSI with as much feature parity with GrapheneOS as possible. Definitely worth a look!