Is his jaw weak from the MBD?
Properly raised and gut loaded bugs should be better than Carnivore Care once he is out of crisis. I don't think the Carnivore Care has any roughage in it based on how much is fed per kilogram of body weight. I think the Carnivore Care should be an emergency food source only.
However, if he is having trouble using his jaw (or tongue) because it is so demineralized that it is rubbery, you may need to continue for a long time. His tongue has a bone in it and it uses bones in the throat to launch it.
You must be particularly careful that your bugs are very, very healthy and well fed. I always prefer wild caught bugs. Commercial food is fed on the cheapest garbage they can get away with. You know the sayings, "Garbage in, garbage out" and "You are what you eat." I read a Consumer Report on bacteria in hamburger, and in the report they discussed what was fed to feed lot cattle. They actually fed the manure from chicken houses. If that is what goes into food for human consumption, I can only imagine the garbage that goes into crickets bred for feeding fish.