Thanks @jmvdv it just amazes me how much info is out there and how much there is to learn.
Dietpi is just the perfect dedicated bridge option and volumio is pretty slick for stand alone setup - even mounts a USB external drive effortlessly on a restart.
With Bridge on Volumio and both hopefully coexisting I hope I can have the best of both worlds…as using volumio from roon via airplay just doesn’t cut it.