for ease of use i would not use a pci coral. usb just is easier. passing the usb through to a dock or vm is easier. i use unraid and it was extra work to get the pcie vs usb coral setup. I have a nuc with a bunch of ssds for this kinda thing too.

Three versions that I know of have it but you’re right it’s not common. https://www.intel.com/content/www/us/en/support/articles/000091705/intel-nuc.html