Awesome thread! I wonder if you can help me.
I've read that I would be able to flash Asrock B450M Pro4-F BIOS upto 2.40 to my old AB350M Pro4 board (can't post link since I'm newbie...) but AGESA 1.2.0.0 BIOSes would likely render the board useless. Any clues or ideas how and what should be tampered with in the newer BIOSes?

If this is all but correct thread for my questions then just carry on...

Hi Fernando, my nvme is not being recognized and I suspect the modded bios is not being flashed even though the AMIgui states it is done/verified. I am using Method B under ASUS.

I again re-flashing the motherboard bios as per the directions. I did not do anything differently this time. When I opened the bios my settings were NOT reset to default. This makes me suspect that the flash is not working even though it reads as complete in the command line for the amigui utility.

I then tried to flash using the asus ez flash utility which of course does not work with the modded bios.

I think you are correct when you said in the other thread that the bio has not been updated with the modded version.