Ok just what in the heck are you talking about? I feed roaches to my leopards and they love them. Granted hissers are too big for leopards but if you use lobster roaches, they are fine.
Now for the chewing through the stomach thing....not going to happen. If you have ever paid attention to your leos they squish and crunch food, DEAD before they swallow it.
The choking thing.....you need to feed appropriatly sized food no matter what kind it is. The correct size roach is not going to choke your leo anymore than the correct size cricket would.
Impaction......no more chance of that than with mealies or crix..both of which have lots of chitin in the exoskeleton too.