dunno about impaction, I think that risk is with mealworms, not supers. As long as your cham is well hydrated it shouldnt be an issue. Superworms are actually fine as a staple as long as theyre gutloaded, and as long as you offer a variety of other feeders so its not 100% supers. Ideally crickets or roaches should be a staple because they have a higher stomach capacity and therefore a higher gutload capacity, but plenty of people here use superworms instead
I think the general assumption is that because they're relatively high in chiton they shouldnt be used, but I think a lot of the confusion comes from mislabeling giant mealworms (T. molitor) as superworms (Z. morio), or vice versa