Yeah, they use them to help set the AOA on the sponsons. With a JAE you wouldn't need it as the sponson angles are very forgiving and there's only the ski on the rear.
Some of the guys are so weight conscious that they'll remove the RX from its box, trim off the servo mount tabs and drill holes in the cases to drop every gram they can. Grams add up to ounces which add up to more speed. Most of these boats are built so that they're expendable as they're shot once a record is set then become shelf queens.