Is this still the case? Would you still hypothetically see better audio performance of something like Discord in a standalone app?
I am sure there are other issues as well. The WebRTC implementation in Chromium is controlled by Google (they have all the commit bits). If they don't agree with your change it isn't going to land. It's a tough position to be in for other businesses and Open Source projects even.
enumerateDevices() should enumerate audio output devices (feature behind pref): https://bugzilla.mozilla.org/show_bug.cgi?id=1152401
Enable by default setSinkId pref: https://bugzilla.mozilla.org/show_bug.cgi?id=1498512
Alex Chronopoulos: "We keep it off because it does not work for everything. It works when we playback a file but not for webaudio or WebRTC. We want to add those too and we keep it off till then."