Currently, installing plasma-pa on a system is impossible without pulseaudio. I'd not like to install pulseaudio on my system due to issues with it that I couldn't fix and would rather use ALSA. Is it possible to make plasma-pa usable as a ALSA volume control plasmoid?
Well, the "pa" part in plasma-pa stands for PulseAudio, so no, it is not possible to make it work with ALSA without completely rewriting it.