When Mo worked for Hammer (the old faball company), he originated the marking of the psa on asymmetric balls. I think the 3-D offset was the first, and the psa was the “hot” spot.
The drilling’s he developed using that core were called (naturally) hot spot drilling techniques.
Now, smart people being what they are, they tend to want to simplify and quantify at the same time, and with some help, Mo did that by finding a better, simpler way to express those same techniques, and that is with the virtually unflappable dual angle system.
Using simple geometry, Mo was able to both quantify and simplify his terms and techniques enough that even goofballs like me could eventually get a grasp of how it works.
As for why cg placement is important on a symmetric ball, Mo explains that with examples of how the core dynamics can either be greatly increased, or decreased, by the addition of x-holes in the proper place. Shifting the cg, using the dual angle system, will allow you to manipulate a balls ending dynamics far more than just putting the pin in the right spot and just throwing the cg anywhere.
That can be advantageous in certain cases. Say you want a ball with a really mild cover, but lots of diff to create track flare. You look, but nobody makes a ball like that, but you MIGHT be able to create it by starting with the right ball, and figuring what angle you need to drill it at to allow you to increase the dynamics to the point you desired to begin with.
Using the system of dual angles and x-hole placement, Mo was able to increase certain balls dynamics by almost 60%!