The good news is mumble supports TCP, works well in high latency environments, packaged for Debian and successfully tested in the past.
Here’s a few ideas for configuring it for easy use so it can be shipped one day:
Somehow create a general purpose wrapper (reusable elsewhere) that generates an ephemeral onion service and relays back the chosen address to WS users for sharing. That will save the user from having to learn how to configure onion services by themselves.
Figure out a way to run it safely with AORTA since its noted to leak DNS requests and does not respond to changes in its network settings. Alternatively DNS requests should be blocked for it specifically since its of zero benefit in this usecase. Make Tor able to handle VoIP applications people already want to use (#5699) · Issues · Legacy / Trac · GitLab
Some of the concerns in the comment and wiki page aren’t really relevant to us since we don’t care about cross platform or non transproxied systems.
A summary of settings that our wiki instructions are based on: