Can you explain why the hitter (and not the swinger) does not have to rotate the plane lines to curve the ball?
Can't the swinger move the ball back or forward?
I believe its Hitters and Hands Manipulated Swingers vs True Swingers in terms of Grip Rotation vs Plane Line Rotation for balls played back of low point. The True Swinger allows CF alone to align Face , Head and Shaft. So by definition, there is no Grip Rotation (squaring of the face) for balls played back in the stance (or back of the clubs unique "straight away position") per 7-2 and 6-H-0 E and F.
We need some drawings here to make things easy (ish).