I have never seen this cup stacking or sever damage to the cap, with the use of the HotShots. Perhaps it's because they treat the effect and not the cause but at any rate, they do work better !! ...
In time this causes all sorts of problems. I have seen cases where the problem was so bad that the hammer would go to half cock after each shot. This amount of erosion would cause a significant safety issue with any type of nipple.
I have never seen this but will certainly be watchful and thanks...
Be Safe !!!