I'd still dust them slightly 1-2X a week when feeding....you can't be sure with every individual batch and also there are many people selling them now under different names where they are so it's better safe than sorry.
That's a good point, AHBD. Light dusting every other feeding shouldn't do much (if any) harm. Personally I've had really good luck with Symton Black Soldier Fly. Their feeders have been really good quality every time I've ordered from them.
How many would you order for a single adult beardie? Symtom's site says they should last 2 weeks... 500 seems like so many, but they don't have an option for fewer. Would you go through 500 in 2 weeks with an adult?
I usually get 500 but they last for quite a long time since I don't use them as a staple. They keep for a long time and will eventually turn into flies which also make a very good treat.
My dragon is an adult so he eats mostly veges. I have a roach colony but rotate bugs to offer as much variety as I can. BSFL are part of the rotation as are silk worms and horn worms and roaches.