@CHBMB
I know you have a supermicro board so I'll add my $0.02
I bought a fresco logic pci-e card because it was recommended by Oculus. However, it caused issues with my supermicro board (X9-srl-f). Basically, whenever I shut down the server, it would restart back up when this card was plugged in (only with linux, though). That caused issues during a power outage as you can imagine.
I tried the same card on a different mobo, an asrock with intel pentium, same unraid os and it shuts down properly. YMMV
I then bought this Rosewill (Renesas chipset) and it worked great: https://www.amazon.com/gp/product/B011LZY20G/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
I have a powered hub hooked up to it and passed through to a Win10 VM for gaming needs (mouse, keyboard, controller, usb headset, etc.)
I can't remember for sure whether I tried to pass it through to OSX to be honest. I haven't touched OSX in a while.