Lindsey,
How does the direction of the club at the top of the backswing (parallel to the target line, laid off or across the line) affect the first move down if the hands push away from the target line as opposed to just dropping more vertically? I like your analogy of the hands pulling the shaft and clubhead like a trailor. I wasnt sure if you had put much thought into it yet.
One of the things I really like about what Brian and team have found (in their research) is that it coincides with the verticality needed to control the shaft from whatever position, it is, at the top. If you strive to obtain low point earlier with the hand path, you certainly would not go "out".
Ultimately, the thing about the position of the shaft at the top (whether across, parallel or laid off) is how you direct the initial torque at start down. We have all read and been told about, as Hebron would put it, "the tiniest move in golf". The hands move backward and away from the target and target line in the transition. This is very similar to the latest manzellian findings. The beauty of all of this that Brian and team are finally getting and sharing THE FULL DETAIL. The great thing about this move is that it will help regulate the shaft angle from wherever it is aligned at the top.
Now, closing the gap and tossing the clubhead still resembles pulling a trailer. To throw anything you had to have an initial pull.