[MizunoJoe]

That sentence from 10-19-C refers to the third paragraph in 10-11-0 (citing from the 6th edition).

You apply acceleration at PP#1 to actuate the Primary Lever Assembly (accelerate the Left Arm, basically). But the Secondary Lever Assembly (the Club) is actuated by Centrifugal Force alone (Release of Accumulators #2 and/or #3).

And no, this a Swinging procedure. No Hitting. No Switting.

This must be done with the right shoulder and not the right triceps, so the part of the sentence in 10-18-C, which is confusing is "further acceleration", which implies something else was accelerating PP#1 earlier. That could only be the right triceps. In a 3-barrel Swing only the driving right shoulder should be applying acceleration at PP#1.