Yes, entirely possible. Not quite as easy as just using the Boot Camp Assistant, which partitions the boot drive, but still doable. You basically just use another PC / virtual machine to set up the separate drive, then install Apple's Boot Camp drivers (downloaded beforehand from a menu command in Boot Camp Assistant) onto the fresh Windows 10. Make sure you disable Secure Boot in Recovery.I just wonder, is it possible to install Win10 on its own internal ssd on the 7,1 (means not on macOS boot ssd)?
So for gaming it would be cool to add a fast NVIDIA and use it for WIN10 on the 7,1.