Yeah, Roon recommends at least Intel® Core™ i3 processor or equivalent. And to install the application on an internal SSD drive.
My current NAS has the Celeron® J3455 quad-core and would require an expansion card for the SSD. The NAS is still technically relevant so it should sell easily enough and offset a big part of the upgrade cost. With a few expansion tweaks, it could take care of all my audio, video, photography, cloud, server, and geek needs. Looks like a pretty doable project.
Last piece of the puzzle is what flavor of Pi do I want ...........
Just need a good digital Roon endpoint. I don't think I would use an audio output.
@nimar What flavor of Pi do you use?