At the suggestion of Mo himself, I drilled my Yeti with the pin next to ring and the MOtion hole.
When I threw the ball without the MOtion hole added, the reaction was smooth but surprisingly over/under.
I started with a5/8" x 3" hole and the reaction became more angular but less sensitive to variations in hand position and ball speed. The reaction off the spot was strong and the lazy spares I had left without the hole were less frequent.
I upped the size of the hole to 3/4" and the flat 10's disappeared. The ball finished through the pins so much stronger it was almost like it was a different ball.
In short I see the MOtion hole as an incredibly valuable tool for the pro shop operator to use when dealing with bowlers who have lower rev rates than they want to have.....namely women and seniors. The ability to make an even stronger reaction for bowlers with an already strong release is also a big benefit to dial in that special reaction.
Great new addition to a pro shop operator's arsenal.