Hello. Did you downgrade successfully using this tool? to do this "MRL unlock" I should purchase creds? I pressed this "MRL unlock" and received 144 error or something like that) Also what exactly this MRL means? Can I downgrade from 12 to 10 android using this and without unlocking bootloader?You can downgrade firmware only if you purchase "MLR unlock" through qUnlockTool
On top of that you will need to find firmware for your specific device because most likely you will run into issues otherwise
I don't have this but I have XQ-AT51_Customized EU_58.1.A.5.507-R26B which I think is the previous updateIf anyone have XQ-AT51_Customized EU_58.1.A.5.530-R2B I would be very greatfull.