Then it sounds like the double thumb may be doing what it is designed to do, but the recovery in my case is extremely weak and definitely not worth the added length. I'll try playing with surface and see what happens. As it stands now, it's a re-drill for sure.
Thanks for the feedback.
The double thumb helps increase the RG and the Intermediate differentials. Larger differentials increase the potential flare. Where that flare occurs depends on the ball's coverstock, the surface applied to it, the amount of oil on which the ball is used AND the bowler's ball speed and release.
If the ball gets long length due to the combination of the above factors, the flare will be applied at the backend, providing a lot of recovery and backend hook.
If the ball hooks earlier, due to the above factors, the flare will translate into more overall and earlier hook.
From my experience at Nationals in past years, you do not want all your hook to be at the backend. That is, you don't want a flippy ball reaction. Often the oil pattern at Nationals is oilier than 95% of your average house shot. You want "SOME"degree of midlane "grab". Again, how much depends on the your release/ball speed and the oil pattern you see. (Remember what you see at Nationals is not always what is advertised.)