I dont think it'll be worth the trouble. The most you'll gain by modifying the gas tank is ~1/2" more travel, and thats assuming you're running 28" long shocks. Most shocks are 27.5" or less which means the shocks will limit travel before the gas tank does.

The next step up in shock size is not practical with our 2-3" lifts because the compressed lengths are too long.

Im not worried about the control are hitting the tank there. The tank is very thick and there's only axle weight at that point. Although if I had some foresight when I was cutting the skid I would have left just enough so the arm contacted both at full drop.