Hello,
A friendly reminder that txtorcon exists and supports v3 onions, (even if developed has slowed somewhat in recent times).
It probably doesn't help onionshare a lot, as txtorcon is a Twisted-based async API so it works best with other Twisted-using code. That said, you _can_ inter-operate with asyncio or even with threaded code if you want. However, it's not going to be a drop-in Stem replacement (and that has never been txtorcon's goal).
https://github.com/meejah/txtorcon/
Documentation available via onion (which self-hosts on the Twisted webserver with txtorcon for Tor support):
http://fjblvrw2jrxnhtg67qpbzi45r7ofojaoo3orzykesly2j3c2m3htapid.onion/