Standard methods usually are not viable for mod files, due to security preventing flashing modified firmwares…well know issue on mod community.
An alternative for Intel based machines…
[GUIDE] [UPDATE] Usage of AMI’s AptioV UEFI Editor + FPT Flash Method - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)
the main issue here is the actual state of SPI regions access, described here:
[Guide] Unlock Intel Flash Descriptor Read/Write Access Permissions for SPI Servicing - Special Topics / Intel Management Engine - Win-Raid Forum (level1techs.com)
A note…this tool (Intel FPT) doesnt care of the content of the files, it flashes all bad or not.
The users should only engage in this process if they know how to recover the system and have done SPI backups, of course they should be a little experienced on this…not a task for 1rst time users.