R-U-S-S

Hi all, first off thanks to all the members here I have found your advise invaluable over the last couple of years! I currently have the following setup and thought I would post here in hope to get some advise and feedback once again. Magma Expressbox 3t (thunderbolt 2) nVidia GTX 750 ti Cheap mac compatible USB card 2 x 256GB SSDs 2 x USB 3 to SATA adapters I have been using this setup successfully in a plug and play setup with both a Macbook Air 11" 2013 and a 13" Macbook Pro 2014 with optimus working on the MBP using the grub boot loader. I have today however taken delivery of a new 2015 13" MBP to which I eagerly connected my eGPU, alas whatever I do I cannot get the GPU detected in windows, the USB card and devices are functioning fine but no GPU! Looks like Apple may have changed something (probably EFI) to block Thunderbolt GPUs? If anyone one is able to provide any assistance on trying to get this working I would be grateful. I have 14 days before I will return this is I can't get it working so I am happy provide any EFI register outputs etc if it helps.