[Daryl]

I'd say the Right Forearm, indeed the entire RFFW ideally stays "on plane", so to speak, throughout the entire swing. But this is the plane of the Right Wrist Bend not to be confused with The Inclined Plane which the right forearm rides sometimes through impact say, but not always. So at top the RFFW is not on the Inclined Plane in Total Motion. Chipping maybe. See 6-B-3-0-1.

Ah ha. I see your problem. The Right Forearm stays aligned to the Swing Plane if you don't over bend the Right Elbow and you use a Rigid Power Package. Meaning that the Arms and Club are lifted by the Shoulder Sockets so the Alignments of the Right Forearm remain undisturbed within the Power Package after the takeaway and during the Backstroke. Then as your arms are lowered during the Hand Acceleration stage of the Downstroke, your Right Forearm comes back down to the Plane exactly how it was at the end of Startup.