The “Pi-based” solutions are pretty much snap-together, though. Simple and cheap. Takes about 3 minutes.
You’d want a Raspberry Pi 4 “starter kit” – no need for a keyboard or mouse. And an OSMC remote, which is a little USB RF receiver that plugs into one of the Pi’s USB ports, plus the remote control wand. You download RoPieee (free; google the Roon forum for instructions) and copy it to a SD card, snap the Pi together, plug the SD card into the Pi, plug the OSMC receiver into the Pi, and plug the Pi into the wall. And bingo, you have a Roon-capable remote-controllable streamer. Which can be hidden in a cabinet because the remote is RF, not IR.
And Pi 4 instead of Pi 3 because of the improved engineering of the Ethernet port. Though it will work with WiFi, as well.