Hello there,
I recently ran your script on my 27" October 2015 iMac with an Akito 2 box and a GTX 960 eGPU setup. My external monitors are displaying and the CUDA cores are functioning but now the internal iMac screen is malfunctioning. By default, the mac boots with a extremely narrow image leaving plenty of unused black space to the left and right. The image reminds me of airplay mirroring an iPhone while holding it vertically. In the display preferences, I can not access the scaled resolutions. I am holding down the alt key prior to pressing scaled but nothing. When I do force a retina resolution via SwitchResX, everything displays super blurry. Lastly, the graphics pane in the system report menu states that my internal AMD GPU is listed as PCIe, not built-in. I have also tried reseting the PRAM and SMC but no luck. The only way I got the display to cooperate was to do a time machine restore but then I lost my eGPU capability.This script was the only way I could get the GPU to talk to the mac but now I am compromising with degraded resolutions. Does anybody have a solution to this issue?