Black Soldier Fly larvae are basically just Phoenix Worms, which are a well established feeder in the pet hobby. No problems there.
I'm not aware of Painted Ladies having any toxic characteristics, and it has occurred to me that they might be a viable feeder option, both as caterpillars and as butterflies. As far as I can tell, the caterpillars are raised on some sort of cookie dough medium, which should be easy enough to make.