the problem is not if uefi windows is booting or not, the problem is that uefi windows write certificates where it shoudnt.
Those certificates
might help an almost full 1st Nvram Stream to collaps.
OpenCore protects (with the right settings) nvram from getting certificates from Windows. Even booting the USB Installer writes the 1st certificate without protection.
But if things go mad, for example OpenCore Drive is missing and the Mac boots uefi Windows without OpenCore protection the certificates get into nvram.
These certificates can't get deleted, with no nvram reset or other magic. Just with Firmware reconstruction (or flashing back a firmware backup without certificates)
At least everyone should have a rom backup to write back a rom without certificates when dealing with uefi Windows.
I have already updated to 140.0.0.0.0 and originally had an EFI install of Win10 on my 2009 MacPro 5,1. After reading about possible bricking of the ROM, I wiped and completed a Legacy install of Win10. Problem is, I still have the certificates inserted from the old EFI install. Is there a...
forums.macrumors.com
How to Backup the Firmware:
#9