Yeah, the pronated takeback is awesome, and I've noticed people deliberately copying that maybe the last 2-3 years.
To get all the action on that puppy. a person needs to eventually have what Will was talking about: the flat swing plane where all the wiping action comes from the forearm pivoting around the elbow. When you get that, not only does the spin go up, but you also get more acceleration through the ball.
This visualization might help. Imagine that the ball has a tall, narrow H on it, and that you want to hit the middle of that H. Or, you can imagine that the ball has two vertical, parallel lines (i.e. "|x|"), and that you want to strike between those lines (i.e. the "x".) You'll know it's working for you if your takeback suddenly gets straighter/more compact.
I like to use that with a smile pattern 2H BH as well, just to get into a person's head to drive through that ball.