In my opinion you really have to base it on the individual chameleon and the physical signs they are displaying. Once they get to the point of showing the extra weight in the cheeks and casque you know it is too much. Trying to keep them in that healthy range becomes the ideal.
Everyone has their own opinion on size…. I tend to be more cautious giving advice on weight because I have helped people and then they do not listen and end up getting their cham far too thin.
I agree with @nightanole your boy is not obese at all as I said before but he is on the heavy side of healthy too. Issue with this is if you do not work to find his sweet spot on food intake without weight going up or down then he will continue to gain. Happens pretty easily and quickly once they start approaching the 1.5 to 2 year old mark. They simply are not growing anymore so it all converts to excess.

