Unfortunately no, wax worms would not make a good staple. They're high in fat and are really only more of a snack food for beardies. Feeding beardies only fatty foods can lead to liver problems, something that from what I've seen happens often. A few wax worms once or twice a week is okay, but not as a staple food.
How big is Lexi? If he/she is at -least- sixteen inches then you could try superworms. Or crickets, they're obviously an excellent staple. Or roaches.