Quoted from Sheev_Palpatine:PinMonk used this technique to fix the bricking issues on the 3 bank drop targets on James Bond 007. I have been thinking of trying this on centaur. I would think it would have the same effect on a Bally but maybe not. Hence my reluctance on trying.
It really depends on what the Centaur problem is. If the target is bouncing back to the shelf before it drops then this would help. If you're concerned about cutting, you could always buy a couple more springs and use those to experiment.