[Loren]

Believe it or not you can.

You can use the #3 pressure point for Extensor Action which has the effect of not only pulling the inert left arm straight but also pushing and extending the club shaft.
You do have to guard against loss of the right wrist bend.
Using Extensor Action with PP#3 alone to power a hitting stroke feels like using a tight right forefinger/thumb grip.

I don't believe that flattening the right wrist would relieve PP#1 otherwise as you're pushing the base of the palm against the left thumb.

A Flip release in TGM (10-24-F) does not mean bending the left wrist. It's a different definition of the term.
It's the pivot-controlled hands swinging procedure.

Flattening the right wrist destroys the Flying Wedges, the accumulator #3 control, the hinge action and thus the Rhythm of the stroke, makes clubface control erratic and results in power leakage.