^FWIW, if you change the direction of tire rotation (however, X, no X doesn't matter) you can always see which tires feather the tread which direction with respect to position, front, rear.
Rotate so that the new tire position is in a position to correct that feathering or essentially feather the tread the opposite direction, it will increase tire life and decrease road noise and vibration.
Hard to explain but easy to see. Pretty much all tires of run in the same position for a while will have slightly feathered tread. Somethimes Can only feel it and not see it if it's real minor.