Does it NEED those P106's though? Can it run 16 cards (8 nvidia and 8 AMD)?
If I remember correctly BBT started with p106's and started adding normal GPU's to max it out instead of the other way around. I would check the latest BIOS/chipset drivers for updates on compatibilty, but 8 normal Nvidia and 8 amd should work fine, or start with 13 AMD and add Nvidia one at a time. The worst part of that board is the crazy loading times and then trying to load OC values after that. Seems more feasible to stick with 8-13 GPU motherboards.
Manual specifies 13 "normal" cards max.
I'm still trying to figure out WHY that limitation exists, there is no LOGICAL reason for it.
As mining cards have no video outputs, I think there may be some system limitations that don't apply to them. That's the only thing I can think of that makes some sort of sense.