i think its a good start to a healthy relationship with your cham..they will still hunt on there own..they are oupportunistic eaters anyway..so whatever is convienient they will go for first..
I agree with others here I think hand feeding helps build trust (plus it's a way cool interaction you can have with your cham that isn't to stressful for him/her), I don't think they would forget how to hunt, but if your worried about it (or just want to make sure he/she's getting some exercise) you can just hand feed a few a day, or every other day and free range the rest (best of both worlds)
Maybe make the hand feed ones a treat (such as a worm or favorite food)
im going to start training my 2 month old veiled to hand feed although he is eating well at the moment....about 5-6 half inch crickets daily.. so.. its good for now..