I would add that this alignment needs to be accomplished without grounding or soling the clubhead. If you do ground the clubhead at address, you to do it after the alignment is established and it will look different as does the location of the clubhead when grounded vs not grounded.

What about with mid body hands at Address, should you still be trying to line up the forearm?

Swinging to the Classics!
 

With a Classical Address, Left Wrist Bent and the Right Wrist Flat, the On Plane Right Forearm and Clubshaft can point at nearly the same point on the Plane Line during Start Up (7-9); works for me. Of course, we know that somethings are going to change before we get to Impact.