In theory you can use the WiFi-One, though I don't know if that one is BIOS-locked. I just use it with USB3 and a 4 Bay Enclosure, which probably someone is gonna explain to me is the worst idea since leaded gasoline, but I have absolutely no Issues with my ZFS NAS for 5 years that way.

Over on reddit I once floated a similar idea but everyone exclaimed that USB enclosures sucks and you should not use them at all. Now technically you could - with some PCIe expansion cards - connect SAS/SATA HDDs to the ports on your mini/SFF PC, but then you need an enclosure for holding, powering and cooling the disks. Holding and cooling is simple enough and there's enclosures on AliExpress that cost like 10 bucks that do it for you, but you'd still need a PSU outside of the PC to power the disks. At that point the USB enclosure starts looking even more enticing.

Which one are you using right now? There's some brands out there that are considered really bad by the community.

Ah, good point, I hadn't considered a USB solution. I might look into that, though I'll have to see if there's a good way to keep all the cables looking tidy and not have a cable coming out the front and then disappearing back inside again haha

Which enclosure? I've got an upgrade on the horizon and like this solution.