apparently only thing better is an nvdimm??? Just did a quick check in the forums here and elsewhere. Historically FreeNAS sees this as a straight up nvme storage device it seems. I don't have first hand knowledge though - just a quick check.
At that price it looks very enticing, could replace an optane 900p in a FreeNAS VM. For me, the next question is whether ESXI 7 will support this as pass-through I guess, but could still be useful. kind of a pain with the F/H bracket but spacing looks like it might take LSI HH brackets and dump the 8643 cable attachment it has.