Need help with Thunderboltex card & crossfire

So I am trying to extend my workstation down the hallway using a 30 foot thunderbolt optical cable. because of reasons...

Specs

Rampage V extreme X99
5930K 40 lanes one.
SM951 m.2 drive
asus thunderboltex II
2x R9 290 Vapor-X sapphire 8GB

Thunderbolt monitor (lg ultrawide)
elgato thunderbolt II dock

So my problem is that I cannot get it to run if I have both graphics cards and the thunderbolt card at the same time.

Without the thunderbolt card crossfire R9's work perfect.

each card individually runs

each card with the thunderbolt card works great. The thunderbolt card does work and the Tower at the moment is in my back bedroom with only one graphics card running across the thunderbolt cable to the monitor and dock.

Only when I try to run both graphics cards does it not work. When I install the card and try to run it I get a constant boot loop ending with q-code 79. the led's marking where it is in the boot process gets stuck on VGA_LED its got to be something with the graphics cards.

some have suggested enabling above 4g decoding, this allows it to run but disables crossfire in the OS.

Any help would be much appreciated.