I agree wax worms are like the kid in the candy store for bearded dragons .They should only be used as treats not as a staple diet.Phoniex worms are also good for them .
It's a no-brainer ===> silkworms !!! definitely silkworms.
They are an excellent feeder insect for all lizards, and very nuitritous.
I was giving small (mealworm sized) silkworms to Peppa and Toothless at 5 weeks old, and they were taking medium (to 2in long) silkworms at 10-12 weeks old.
I essentially substituted 6-8 small silkworms for a live meal , or 2-4 medium silkworms for a meal.