Hey,
BIOS: ROG MAXIMUS XI APEX 1302
- Full Unlocked
- Downgrade Microcode for CPU signature: 000906EAh Revision: 00000070h Date: 23.08.2017 ( No Spectre/Meltdown fix )
- Capsule Restored
( Always do a full BIOS Backup, just in case! )
1. Put the BIOS-File M11A.CAP as it is, into USB Root Folder.
2. Shutdown PC.
3. Unplug Ethernet Cable. ( I saw wierd activity on ethernet led, when i used Flashback with it plugged. )
4. Press BIOS-Flashback Button 3sec, when it start blinking it will read the BIOS from USB.
If the USB shows Blinking Activity, BIOS get Updated. Dont Interrupt that process. (3-5Minutes)
5. If Flashback Button LED, turns off. Its Done.
6. Start PC.
If something doesnt work, use the original ASUS Flashback file to restore BIOS.
If that doesnt work, you will need SPI Flash Programmer.
I take no responsibility and I am not liable if something does not work.
Have Fun 
PS: Tested on 2 Mainboards, worked.
Download:
https://mega.nz/#!0IMGEQZL!E03W3Xh5wEl2L…mDiuhzDSVmNTS5M