CXRT - SAS to usb 3.0 adapter - weird sata stance

i'm confused. most sas controllers are backwards compatible with sata afaik.

But in the manual for this product they warn against hooking up a sata drive to the adapter.

i picked one of these up for 59 euros and i'm not sure how i feel about it. (i do have a sas hba anyway as a primary way to utilize sas drives)

Initially i figured "this should just be a sata-usb interface that also supports sas" but i guess not?