Asus X299 Tuff MARK 2 Bios 3501 mod Request

I have been following a guide here from Lost_N_BIOS on how to unlock the BIOS Lock bit utilizing the "Grub Fix Intel FPT Error 280 or 368 - BIOS Lock Asus/Other Mod BIOS Flash"

Once I have the USB ready for boot and disable secure boot and UEFI then select launch EFI Shellx64.efi (or Shell.efi)(tried both types) from USB the system hard locks and shuts down.

It then requires me to switch the power off at the wall in order to boot up again.

But now i am stuck…

The only setting I’m looking at modding currently is the one bellow;

“High Precision Timer variable”

please make available in bios as changeable or OFF permanently if its not allowed to be shown in bios as a setting.

Thank you.