I have managed to downgrade thanks to someone in private message. and now instead of having from before ME FW 11.8 + ME FITC 11.0 i have ME FITC version 11.6 (and fw 11.6 too), strange. static audio sound is unchanged but the whole system is a LOT faster, incredible. didn’t tried games yet.
The bios version 0401 had unlocked ME read and write. i used usb flashback to flash it, still had me fw 11.8, then i tried to use the tool under windows but still refused. i then tried to flash bios 3802 with usb flashback and it worked!
edit: yea games are clearly more fluid, fps seem much more stable, no microfreeze yet even if they didn’t happen very frequently before, i didn’t tested long enough.