[Request] Unlocked ROG Strix Z690-A Gaming Wifi D4 BIOS

[MeatWar]

Additonal useful threads besides the one already linked by you:

[Guide] How to flash a modded AMI UEFI BIOS - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum

[Guide] Usage of AMI’s AptioV UEFI Editor + FPT Flash Method - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum

[Offer] ASUS ROG STRIX B760-I BIOS MOD - Unlocked Hidden Settings - BIOS/UEFI Modding / Offers: Already modded special BIOSes - Win-Raid Forum

The mb model has USB BFB feature, so its easy to flash mod files, perform an fpt backup of the current system, full spi or bios region at least.

So read, learn, do it yourself.