My personal experience is also based on a long PAP. Mine is 6-1/4 left, 1-5/16 up. However, my primary layout is 97-1/2 Drilling Angle x 3-3/8 Pin to PAP x 41 Angle to VAL. Those numbers place the Pin precisely 3-3/8 from my PAP and 6-3/4 from the center of my thumbhole. For most balls, symmetrical or asymmetrical, that produces the most track flare and ball reaction of any layout without a balance hole. The 6-3/4 from Pin to center of thumbhole is significant because it places the largest hole in the ball directly in the side of the core which increases the drilled Int. Diff and Total Diff.
My preference these days is not to vary the layout, but to vary balls and surfaces. If I was a staffer, and limited to certain balls, I might be more inclined to vary layouts, but I find it unnecessary with the huge variety of balls available. And, I am confident knowing I am using the strongest layout for my release specs, along with a familiar hook shape. Btw, that layout is not for everybody, as it has the potential to flare over the thumb for bowlers with over 300 RPMs.
Years ago, when I first started drilling my own equipment, I experimented with a huge number of different balls and layouts until I started to see a pattern emerge what scored best for me. It was around that time I purchased Blueprint and it confirmed what I knew intuitively. If I had only purchased it sooner, it would have saved me thousands of dollars.
I've read an article from 2012 I think from Blueprint regarding flare potential of bowling balls. They picked three balls (strong asym., medium asym. and a symmetric) with high differential ratings. It seems to me that if one wanted their ball to flare well they'd pick a drilling angle of 50 degrees. For an asym. ball they'd pick a pin to PAP distance somewhere between 4 1/2 to 5 5/8ths and for a symmetric ball 3 3/8ths. For a VAL angle they'd pick one on the lower end of the scale like 25 degrees. This would be a 2:1 ratio of drilling to VAL angles. Am I understanding this correctly?
I just had two balls drilled recently and their layouts were pretty close except one was an asym. and the other was a symmetric. The two balls were the Dark Legend and the Wreck-It. The Wreck-It seems to have a stronger back end. My guess is that I should have asked the PSO to take the VAL angle down from 50 degrees to 25 or 30 degrees on the Dark Legend and increase the pin to PAP distance from 4 to 5 5/8ths or so. Then the Dark Legend might have had the flare advantage... Hope I'm on the right track...