Don't know if it will help but...

Pitch changes to adjust ball roll . . .
This info is from a session with Mo Pinel and Del Warren. They do advocate pitch changes to adjust ball roll.

They start with what some here have called the "claw" grip. That is, a bowler's standard fit will include more forward pitches and a shorter span than has been the norm for many over the last few years. When the thumb is fully inserted and the fingers are laid across the holes, the edge of the hole/insert close to the thumb will be between the first and second crease/joint. They feel that a closed hand can remain more relaxed and still hold the ball without grabbing.

Once the "standard" fit is determined, adjustments can be made as follows (for right handed bowlers, lefties need to reverse the lateral adjustments) :

* To Increase Rev Rate - add 1/8 forward to both fingers and 1/8 reverse to thumb

* To Decrease Rev Rate - add 1/8 reverse to both fingers and 1/8 forward to thumb

* To Increase Axis Rotation and Tilt - add 1/8 left lateral to all three holes

* To Decrease Axis Rotation and Tilt - add 1/8 right lateral to all three holes

* To Increase Roll for low track players - Add 3/8 reverse to middle finger and increase middle finger span by 1/16. Add 3/8 forward to ring finger and shorten ring finger span by 1/16.

* To Increase Axis Rotation and Tilt for very high track players - Add 3/8 forward to middle finger and shorten span 1/16. Add 3/8 reverse to ring finger and lengthen span 1/16.

* Two or more adjustments may be combined for more dramatic results.

btw, what pitches do you have?

See the link in my sig? click it.

Making blanket statements in regards to individual situations is dangerous at best...each individual situation need be dealt with on just that, individual.
The elite or those at the highest levels do NOT use multiple grips or spans so why would an amateur choose to? To eliminate some of the cracking, try a thumb hole without using an insert or slug...but I would NEVER recommend a different grip between pieces, too difficult to switch between frames or shots. No disrespect but this game is difficult at best, why make it harder?

I agree that you might have a problem switching grips to shoot spares, but if you are determined to try why not use a conventional grip instead of finger tip?  --  JohnP

I currently own the ICE storm...

I've used UFO and other non grit polishes during the season reapplying every x no. of  games. It's the thumb hole cracking that I want to avoid. I really didn't give it much thought about going non slug. But, it's a possibility and it makes sense. 

With that said, I did give a little more thought about trying different grips since I'm off for the season, knowing there are detrimental effects doing this experiment.  But the great Michael Jordan once said, "I can accept failure, everyone fails at something. But, I can't accept not trying."

The conventional grip with spare balls I've seen done before. That's an idea, thanks John for the input. Will grip changes work for me, I'm not sure till i try. I doubt I'll get used to these changes since I'm a "feel" type player, but this is for fun and to fill my curiosity. The challenge is finding an operator that would work with me.

 

I will reiterate what I said earlier...
I would NEVER recommended varying grips or spans...you may be correct in regards to Barnes using differing pitches but he is one if the best technicians...he works at the game as we do a normal job...he is the anomaly not the typical...thus I would not recommend copying but hey...

Update:

Couple of weeks ago, I picked up one of my old naturals at the storage facility to see how it felt to throw 1/4 rev pitch. Added tape to make the thumb snug and BOOM!!! damn dropped the ball by my ankle...Added more tape and more tape.  My hand felt tired after the first game though.

Maybe the combintion of not bowling often like I thought I would, or the reverse pitch was making me grab/pinch even with a tighter thumb was making my hand tired. Also, it just didn't feel right. Switching to the other balls on the second game, I hung up once. Then switching balls with 1/8 forward to 1/4 reverse took some mental work. The feel was worse. One ball had two tapes, one front and one back. The other ball had 4 in the back 2 in the front.

Eventually, I got used to it but my hand was fatigued. I think for me, no slug on my spare balls is a better option and keeping my current pitches (1/8 forward) for the thumb.