I sort of had heard of pipewire - but only to the extent that it was the next audio/video stack.. No idea about how far along it was. Also no idea that it had the BT headset thingy all sorted out.
Your comment made me go "huh! that's easy enough to finish off in 10 now" and provided the impetus I needed
It was even easier to setup on my desktop (now running Manjaro rather than Ubuntu because of SteamPlay/Proton et al) and simply `sudo pacman -Sy manjaro-pipewire` followed by a reboot. If it complains about pulseaudio related conflicts, just `pacman -R` the packages it mentions then try manjaro-pipewire again, and then reboot and you're done.