Asrock Z390 Extreme4 Biosmodding for downgrade

Hello friends i want to downgrade my Asrock Z390 Extreme4 from P4.30 to P2.30 i read here that the Bios must be modded before downgrading

Motherboard came with new Biosversion but its crappy

i did dump bios with FPT tool LOST_N_BIOS mention in a other thread and i checked wich ME version i have its CSME V12 i downloaded Systemtool and had no errors in dumping and reflashing so you need that Bios dump?

@ LOST_N_BIOS can you do it for me i would donate your work or can you explain the next steps.