Ken,

> I am not able to provide much help, but I have some recollection of
> having to use
> aplay to override the default firefox audio on an installation of
> daedalus, thus accessing
> alsa directly.

Interesting. How did you do that?

> If I recall, and don't bet on it, firefox is built with
> support for alsa and pulseaudio,

My understanding was that pipewire should support both pulseaudio
and alsa interfaces/APIs. I might be wrong.

    Julf