I've used fully passive Atom Mini-ITX systems from ASrock for oVirt for the last years. Contrary to Intel's documentation they can be upgraded to 32GB of RAM and I've also added 2.5GBit RealTek USB3 NICs for a bit better Gluster throughput.
I currently have one of them running Xcp-ng, unfortunately without support for the 2.5Gbit adapter so far, but the console is working.
The RealTek source code driver is an #ifdef nightmare, it won't compile clean on CentOS7 and I had to patch an older variant by hand to make it work there. Support on CentOS 8 was also a bit shoddy, endless diagnostic messages with the built-in driver, but functional. Abandoned that when CentOS EOL got announced.
Unfortunately Xcp-ng 8.2.1 loses the display on my Ryzen 5800U based notebook, just like all other more recent hardware devices I've tried, so I'm a bit surprised the 4700U works, when it's essentially the very same iGPU: does the Minisforum support legacy boot and did you use that?
Because I'm under the impression that the display loss is related to UEFI issues.