If unraid can see it, then it's simply a matter of understanding how the drives are laid out in the OS under /sys/devices. SATA, SAS, and NVMe drives are all represented differently. The best way to do it is to have such a controller but I've already made too many expenditures to pick up a card to add support right now. If you're willing to help me find the information to add support (will be a bit of back-n-forth), send me a PM.
I'll also add support for a "Unidentified Controller" to stick any orphan drives under.