Please make it. I will think later how to flash it. I had some experience in-circuit debugging with programming mcu. I don’t think it’s more difficult.
It seems that mod can be flashed with SPI flash programmer only (as here https://forums.mydigitallife.net/threads/award-ami-bios-mod-requests.5863/page-3116#post-1475389 ) - in the latest Asrock's BIOS the BIOS digital signature verification is strengthened.