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I moved to Pale Moon. It's all right, just the JACK backend in cubeb came back apparently *after* the fork so its native powers are kinda missing. I can still get audio "my way" following this guide but then of course JACK has to always be running unless I feel like manually and temporarily telling ALSA apps to use anything other than default. Which is fine-- JACK is pretty much always running. After I work out some theme-related weirdness in the urlbar, or just give up on that theme, I expect to have totally torn off the bandaid.

Of course I can just USE="-pulseaudio" and things are OK (for local builds only) but I'm finally just voting against Mozilla's madness. Pulse was acceptable only because it was mandatory for having my mic work in Xubuntu for voice chat in L4D2 and that's all, 2014 was the last time. I eventually had Pulse insisting on using the rear Mic jack because the front one just didn't have the proper Azalia design & wiring, in order to indicate a plug was inserted. Of course ALSA lets me mute/unmute both if I want... Rather than fight with it, I just set up my audio kit so JACK would start and in qjackctl's post-launch-script, pulse would get killed so that it had to restart as a JACK client. Then everything was fine, I could just use whatever Mic I knew I wanted and adjust it with alsamixer, and connect the alsa capture outputs to the Pulse inputs in JACK. I kinda hate it when a piece of software is too smart by half and then gets it wrong so that making it work correctly is significantly harder than manually configuring ITFP, putting together the UNIX-like worse-is-better bits-and-pieces MYSELF. That is one of the things that Windows was really "good" at. That is why systemd is Somebody Else's Problem. That is why telling me that portage needs to add media-sound/pulseaudio to my package.unmask is a shooting offense.