Thought about this and I think it is not showing up because of the ScanPolicy Config Key since as UEFI Wiindows, it is in an EFI partition and these are set to not be scanned in the OpenCore config created by MyBootMgr.
Change the "ScanPolicy" value to "0" which scans everything.
Hullo Dayo; So I've now had time to sit and get this sorted.
The RefindPlus/Opencore chainload combo is far and away the easiest and most reliable BootLoader I've had the pleasure of using.
So where as previously I could get;
Mac to Boot 10.13.6 with AMD.
Mac to Boot 10.13.6 with Nvidia.
Mac to Boot Win10 with AMD.
Could not get;
Mac to Boot Win10 with ANvidia.
This morning I uninstalled the whole bootoader shebang, (Opencore and RefindPlus). It couldn't complete for some reason so I took my dedicated Bootloader drive and used Win10 in parallels to format it as MBR.
I then did the NVRAM reset thing and put the AMD back in, (the 1070 wouldn't boot to recover either).
Next step, disable SIP.
Boot back into the Mac OS with the 1070 installed and choose the Nvidia webdriver.
Reboot and make sure all is good.
Format the BootLoader drive as normal to give my back my EFI partition.
Downloaded MyBootMgr 0.64a and went from there.
On first reboot on completion everything showed as good. Ran the Mac OS to check anyway.
Shutdown and rebooted and this time chose Windows. It loaded beautifully. As soon as I was in the PC recognised the 1070 and asked if I wanted to update the driver, which is what I'm doing now.
Just wanted to say a sincere thanks for all your work.