Because caused by wrong illusions, there were made serious mistakes while making compatible classification
It was not about the restrictions, but setup lack and lack of alien drivers, thats why:
FZ50 GT4 = +2%/0kg
XR GT4 = +2%/0kg
FXO GT4 = +1%/0kg
These will be final restrictions no matter what, let's see later then if having problems with these