[Yoda]

AND if we are assuming a 10-2-D grip, the Right Wrist Bend and Right Forearm are NOT AT RIGHT ANGLES TO THE LEFT ARM PLANE.

Not so fast there, Colonel. The 10-2-D Grip mandates only a Turned Left Wrist. The Right Wrist remains Vertical and the precision alignments of the Right Forearm Flying Wedge remain intact.

Further, the Turned Left Wrist does not negate the true Plane of the Left Arm Flying Wedge, i.e., the Vertical Plane of the Left Wristcock Motion. The only difference from the Vertical Left Wrist version is that the Turned Left Wrist (cocked in a Vertical Plane) will produce a Double Wristcock. That is, the Left Wrist not only Cocks, it also Bends.

And the Right Forearm Flying Wedge is indeed placed perpendicular to this Plane of the Left Wrist Double-Cock Motion.