Your PM box is full.

Bump stops are like helper springs when you get to the end of the suspension travel. Bottoming out would be harsher with shorter stops, since there is less rubber to absorb the hit.

How hard do you drive the car? Do you carry a lot of weight in the back? If your hard on the car it might be worth it to confirm what you have.

Talk to the guys at Speed Element, let them know what I found and see what they think. I'm not a suspension expert.