If your intention is to Trace a Straight Line Base Line, your Pivot will comply and you will be Hands to Pivot. Like bending over to pick something up, your brain sends your hand to the object, the body complies perfectly, without any thought to it. No need for conscious adjustments to waist bend, shoulder to hands alignment etc. We are well suited to this sort of movement we do it all day long. Take your pressure points to Top and then Trace or Thrust them at the Aiming Point on the way down. Thats about all there is to it.
The plane of the Shoulders and the plane of motion of the Hands do not need to be aligned. There is no mechanical reason for it. No benefit to be had. We dont reach for things in that manner outside of golf why do it when golfing? The body, the pivot , the shoulders go their way , the hands and arms go another. With the shoulders and arms united as single unit a conscious turn of the shoulders , Pivot to Hands will take the Hands back in the direction that the Shoulders are travelling............always under plane. Although some schools of thought then try to align the plane of the shoulders more closely to the inclined plane on the backswing. But why bother? Its a very awkward compensation.
That said, getting the Hands on the Inclined Plane defined by the Turned Right Shoulder ( the Turned Shoulder Plane) prior to Startdown does serve a purpose. Given the 6-M-1 Downstroke Sequence it will allow a move of the Right Shoulder to take the Hands Down the Inclined Plane in Startdown. To initiate Startdown with an independent movement of the Hands or Arms would break the Pivot Train. A movement of the Right Shoulder with the Hands aligned to a higher plane would take the Hands out over the Inclined Plane. But its still Hands to Pivot if, as in the Startdown Waggle exercise, the turn of the Pivot pulls the butt of the club towards the plane line, base line. The brain is still in the Hands. Most likely felt as a strong sense of the #2 pp being pulled longitudinally and the #3 pp being loaded.