Hello Nellie!
I "gut load" all my feeder insects before I give them to my Chameleons. I use carrots, collards, fish flakes, oatmeal... basically any nutritious foods in my fridge at the time. I use a little of those commercial insect foods as well. I figure if you start with healthy bugs, you will have healthy lizards. Sometimes I think I spend more time feeding my bugs, then I do feeding my animals! LOL
That being said, I will still shake and bake my crickets with calcium/vitamin mix once a week to ensure my chams are getting the proper nourishment.
I'm not sure as to the "dusting" regime for leos, perhaps others can give you insight on how often to do this for those guys.
Congrats on the upcoming new arrivals!
Trace