What about the two right fingers of the right hand?
 

I was swinging today on the range and getting great results by focusing on the two right fingers of my right hand.

On the backstroke I sense a pressure in those two fingers as I make my right forearm take away.

On the donwnstroke I was again keeping my focus on those two fingers, specifically the pressure behind the shaft which seems to be kissing-cousin to the right index finger.

The book does not mention these fingers and I find it curious as to why?

Seems to me that you would have to secure those fingers to keep PP1 pressure. You can definitely feel PP1 much better IMO if you focus on middle fingers and the cup.

The pressure in the two fingers in your right hand could indicate you are eliminating or minimizing wobble in your right forearm flying wedge.

I think this is true
 

I think you are exactly right on this one. I'm sure this is happening and the reason for the good results.