When I want to stock android one plus 6 t I need to reparation

I have a one plus 6 t 128 gb.when I use the MSM tool is reparation automatically memory back to stock? ,whith 128 gb or need to use parted to revert back memory because I have 16 gb android and 90 gb win and I want to have 64 win 64 android.Thx in advice.

same case with me,but different device,mine is pocophone f1,how to change the partition size procedure?

Is more complicated to pocofone f1