Veiled are a tricky thing to be specific about when it comes to feeding. At the risk of offending, I am not sure where the quote comes from that says "At this stage of life they should have access to as much as they can eat " but I disagree quite strongly. A lot of Veiled suffer from MBD and one of the causes is over feeding.
A Veiled will eat whatever is shoved in front of it when small and will grow at an amazing speed. This is often at the expense of its health and its bones. "Young calyptratus grow extremely fast in captivity probably due to the greater abundance of food items available than what they would find in nature. This rapid and unnatural growth has cost the lives of many thousands of these captive animals because they are not supplemented with enough balanced minerals to keep their bones growing the same rate as the rest of their bodies." (Linda Davison, Chameleons, Captive Care and Breeding)
Some books suggest that heavy feeding, with correct supplements, is done but then on one day a week no food is given. A slower growing Veiled will live longer and breed better than one grown fast. None of ours have ever eaten 25 crickets a day and they are very healthy, breeding and giving large egg clutches. And 3 crickets every other day is far too few in normal circumstances.
As adults we feed ours every other day. Gravid females may be fed daily but otherwise all follow the same regime. Juveniles are fed well 6 days a week and starved on the 7th.
How many crickets? What is the temperature, the size of the chameleon, its mood, its stress levels etc? 6 large crickets every other day sounds close but maybe low. I probably - on average - feed them between 6 to 10 but they are bigger chameleons. And also individuals - some are gluttons, others like to ponder before they dine. On colder days (ours live outdoors most of the time) their appetites dwindle noticeably.
Fooble is spot on with his comment about the need for calcium. But you also need to check that the UV light is in good order and the right strength - and close enough to the animal to give it UV.
Vary the diet if you can. Silkworms, cockroaches and moths/butterflies are all good. The adults of the soldier flies - Gaga grubs/phoenix worms are taken with relish. I don't feed mine mealworms.
Giving a daily number of crickets is a dangerous game. Fooble suggested that a deep box is put in with crickets inside. That's a good idea and you can guage how many he wants to eat and work from there. Your set up and chameleon will be different from everyone else's.
David
http://www.sa-chameleons.com