Suffice to say, the swinger using angle of approach is in 'effect' rotating the plane line, but is compensating via power package 'support' that is now out of alignment. Less than ideal for a number of reasons.
I don't get it though. If the Angle of Approach is defined as the line from Impact Point to Low Point . . . what's the big deal it's all on the Plane? Plus in the 4th Edition Mr. K said it was a Swinger/Drag Loader's procedure (of course he changed it). And then there's the quote about Thrust being Cross-Line.
Angle of Approach is associated with Hitting, even if the Hitter is not using the Angle of Approach Delivery Line. Notice how with Right Arm Thrust, the Clubhead travels more in a straight line on the same Inclined Plane (Square, not Closed). This contrasts with the Swinger's Arc of Approach (not necessarily Delivery Line) where the Clubhead travels in a more circular fashion.