Sorry, been gone for awhile. I busted my screen in my all in one pc. I ended going through three builds to get the build I was happy with. Surprisingly, I was able to keep my original nvme drives and I didn't have to reinstall my bootcamp.
I have tested parallels 14 and 15 including the business subscription edition. The business version does allow the ability to choose any bootcamp partition or drive. The non subscription version does not. Even though it's only suppose to work with bootcamp on the same drive as OS X, you will be given the option to select bootcamp and it will configured it even if it is on a second drive the first time you configure parallels.
How is your bootcamp currently installed? Are you having trouble with bootcamp booting in general? or just issue with parallels?
other thoughts when installing.....
A. If you have to reinstall windows 10 on the same partitions. - Parallels should be able to pick this up when you go to configure it. If not, there is ways around this.
B. let say you decide you want another copy or move windows 10 to second drive.....
1. If you know ahead of time you want a couple of boot camps, then you would install bootcamp on the 2nd drive. Backup those configuration files. Disable that drive in the bios and proceed to install bootcamp again on the same drive and configure another parallels bootcamp configuration.
C. You can also format a second drive. Install OS X on the second drive. Disable the main drive and install bootcamp. boot the second OS X and install trial of parallels and configure another boot camp. re-enable the main drive and you should be able to import the 2nd bootcamp configuration. I think you can just run that 2nd boot configuration without having to import it and it should work.
I'll try to list my experience from bootcamp from memory.
issues:
1. I use clover EFI for my boot selection on my main drive. I also kept a usb clover boot key as emergency to boot back into the Mac OS. I can then just copy the Microsoft EFI directory in case it gets wiped.
2. Create your own windows install thumb drive either with Rufus or window media creation tool. I didn't have any success trying to have bootcamp create the installer. It might have something to do with the windows iso is now larger than 4gb.
3. If you are installing windows on the same drive as OS X... It works best if you install OS X first.
**** I either physically remove or turn off all disks expect the install drive and the destination drive. Especially if you are installing windows on the second drive. I think the installer creates the correct partitions and analyzes the other drive and either thinks there isn't enough space or incorrect format type.
4. If you are using usb boot drive, then you really don't have to fix any EFI partitions. If you clone clover EFI to the Mac OS EFI partition you will have to copy the Microsoft EFI information over. There is instructions available to prevent windows from breaking the clover boot files. Not an issue if windows is on a separate partition.
