Enabling libspa-alsa breaks Pulseaudio (on PostmarketOS)

Context here is https://gitlab.com/postmarketOS/pmaports/-/merge_requests/5091: PostmarketOS would like to install PW/WP by default in order to handle cameras and screen recording - but is not ready yet to also transition away from Pulseaudio. Also, PostmarketOS does not yet use systemd by default (not sure if that matters).

Unfortunately running Wireplumber breaks audio in the default configuration. One way to work around the issue is to comment out

#  api.alsa.*      = alsa/libspa-alsa

in wireplumber.conf.

Now I wonder: should Wireplumber detect that Pulseaudio is running and disable the ALSA plugin itself - and if that's too involved, what would be the best way for a distro to make this happen?

Should the Pulseaudio package maybe drop something into wireplumber.conf.d - and if so, what?