He looks great! At that age you can pretty much feed them as much as they will eat. Just make sure you give him some variety and are properly gutloading the crickets to increase their nutritional value. Also make sure you are lightly dusting your crickets with calcium and vitamin supplements. The most trusted schedule is calcium w/o d3 every meal, calcium with d3 twice a month and a good multivitamin like herptivite twice a month. You don't have to worry about overfeeding until they reach about a year old but at that time most chameleons metabolism slows down and they won't want to eat as much. At that age most people feed about 6-8 adult size crickets(or equivlient other instect in weight such as dubia roaches) every other day. But like I said he looks great and healthy. Keep up the good work.
-Alex