Great review Adam!
One thing I must interject on … is that all of our gaps are the same. Haven’t changed them since we started. Don’t know who is measuring them, but their tools aren’t working so well. What we have changed though and what people might be saying is gap width is the depth of the response pads. Our Snow Tire response pads are 0.085" thick. For the Chief we changed the response groove depth to 0.090" (.005" recess), but for the Petr Kavka Chief we tried .085" deep. For the AC we tried .085" deep and same with the Glacier Express. Petr likes to use Center Trac bearings and I believe so do a lot of our other team members. Having flush pads makes the return top play better with a center trac bearing. Flat bearings still play great, but you may need to break in the pads a bit until it plays perfect for backspin tricks.
Thanks for taking the time to do this Adam! WOW! Great photos too 