I apologise for the previous answer by the previous user, it really doesn't address your issue..
I'd go for this
www.hardkernel.com/shop/odroid-h4-plus/
I've been using the H3 Plus for a few years and had no issues with it. The only thing you need to do is use the non-kernel realtek drivers for the nic. I'm pretty sure Rod from the forum also uses one.
Waveshare also have this setup
www.waveshare.com/product/raspberry-pi/b...ule-box.htm?___SID=U
I'm currently running a mill with the C box but you're situation would be better suited to the A box.
I like the fact the case and connectors are well integrated, full size HDMI ports, all but the power switch, Serial console connector, and the connector to power it from a non-usb supply (meanwell would be a good choice) are on one side.
The only caveat is that the NIC is a realtek based one, but as long as the cnc stuff goes thru the RPi interface everything should be ok.
Langdons would please provide an answer relevant to the question, the user was looking for a small form factor PC, almost a similar size as a RPi5.