For me, Volumio works perfectly with a Laxton brand miniPC. Handles all hardware elements properly. It’s true, I connected it to a monitor via an HDMI port once to set it up. Take a tip: Forget about WIFI, because it’s just a problem. If you absolutely need Wi-Fi, buy an AccesPoint that you can connect to your PC with a LAN cable. Since using this method, all my problems have disappeared! Before, I just struggled with the different dongles. If the case of the PC is beautiful, then you have won. I don’t want to pry into anyone’s psyche, but most PI houses are terrible. It is true that my PC has a fan, but it can be turned off in the BIOS, and it would only come back to life if there is a problem. So far, it has never revived, even though the machine runs in 0-24.
Not all rPi cases are terrible:
some alternatives are coming very very soon 
Hello,
Fanless, silent and always cool RPI 4…
actually quite simple.
A chic aluminum case with a little more space (in my case 50 x 178 x 220 mm, thickness of the aluminum box 1.25 to 1.5 mm) a Geekworm Raspberry Pi 4 Model B case armor and this lying on its stomach with heat pads with the case screw … 32 degrees are then standard. With Hat-DAC you have to improvise a bit but that’s no problem.
Mine often runs for 10 hours and doesn’t get over 33 degrees at a room temperature of 20 degrees. It doesn’t get any better than that. Incidentally, this also works with a Flirc housing with the hot side down…remove all plastic, of course. The thermal pads (somewhat thicker in the case of the flirc) and a good mechanical connection are important. Two 2-3mm screws are enough. This RPI 4 does not exceed 33 degrees either. Of course only optimal for USB-DAC.
yes…i hate it when my player gets hot…i really feel sorry for my RPI… 
The Toslink cable was the easiest way to bring the status LED SD-CARD to the front.
2 x 1mm thermal pad strips are enough.
here in operation with CD
Argon…before this player was mounted in this same Argon ONE case…wasn’t my thing.
greetings:
Torsten
I agree. I bought a Beelink i5 mini computer to run Volumio on. It’s not fanless, but it’s nearly silent tucked away in the stereo cabinet. It boots fast, searches fast, great connection with my Android tablet. The Volumio system boots from an internal 500GB m.2 SSD drive and my music is stored on a 2TB external SSD drive.
The Raspberry PI is very good but also your setups look cool. We can also add a Nano Sound DAC that is very nice.