https://egpu.io/bootcamp-setup-guide-tb3-macbook-pro/
Step 1. Ran DDU and turned off auto driver installation in windows settings
Step 2. Used the USB key method for the efi trick
Step 3. Not applicable for my machine (2016 13in MBP nTB)
Step 4. Fixed error 12 with combination of step 2 and disabling the iSight/FaceTime camera
That at got rid of all errors except for Error 31 (no driver).
I then went to device manager, clicked on the eGPU and clicked Update Driver-Update Driver Through Windows Update. Windows update found and installed the correct AMD driver and the AMD utility/AMD XConnect.
A couple random restarts and hangs at first but then runs smoothly. I keep the Blackmagic plugged in at all times and can boot into High Sierra or Windows 10 1803 at will. I keep the USB key with the EFI trick plugged into the back of the Blackmagic.