This is a great option. I’ve been through three iterations of this for my work desk over the past few years. Here’s a quick list. For all three, Roon server and speakers are unchanged:
RoonServer running on an old MBP in the basement, ethernet
Desktop speakers have always been a pair of Bose Companion 2
First Setup
rPi 4 w/ a HiFiBerry DAC+, rPi 7" touch screen, Ropieee, ethernet
I have a smaller desk so space is premium and this was just too big and too bulky, and the device is oriented in a way with the RCA cables and the DAC+ that just didn’t work for me. Love the setup though, have multiple of these with various HFB hats throughout the house, so I now use this rig to power our basement audio.
Round Two - Schiit Stack
Homegrown rPi w/ 3.5" screen all in a form-fitted case, ethernet, RoonBridge →
USB out to Schiit Modi DAC →
RCA out to Schiit Magni Heresy (later replaced with the Piety) to speakers
This was a great setup, ran it for 2-3 years, loved it. Small, compact, sounded great, and the Pi screen was running the Roon web extension so I had a nice now playing screen and basic control without opening a full Roon client. But over the years I found myself wanting to route my PC audio (for things like Nugs and YT) through the speakers. While the Bose does support two simultaneous inputs, unfortunately where I live the headphone jack out of my MacMini picks up terrible interference, and on the weekends when a lowfi talk radio channel in my area gets FCC perms to jack their power, the cable became a perfect antenna.
Current Setup (Endgame for this desk setup?)
WiiM Ultra:
Input 1: Roon via Ethernet
Input 2: MacMini USB → Schiit Modi → RCA to WiiM
This has been an excellent setup for the past two months, really love it and ticks all of the requirements: Small, stackable, screen, screensaver clock (a huge bonus as this is my work desk), basic Roon control (the remote is a nice addition I didn’t expect to even use), easily changeable between Roon and MacMini sources via presets, and no more talk radio bleeding into the desktop speakers. I originally chose the Ultra thinking I could use the HDMI out from the MacMini to the HDMI in on the Ultra but the Mac doesn’t support Arc out and then WiiM doesn’t support USB in, so I had to re-use the Modi. Works great.
That was a very long response to say you have tons of options, all at very reasonable prices, assuming you don’t go with the dongle approach.