Important when free-ranging feeder insects...
Remember not to leave insects roaming around the cham's enclosure overnight.
The most important reason is that insects will lose their gutload overnight (i.e. they digest what they ate and then secrete it as waste), so unless you leave gutload in the cage (also not a good idea due to frequent mistings, chameleon droppings, bacterial growth, etc.) the insects will have lost the nutritional value that you carefully prepared for them when you originally fed them to the cham.
Also, the roaming insects could quite possibly snack on your cham's droppings, and that's not the sort of gutload you want to pass onto your cham.
And free-ranged crickets left overnight could potentially attack the chameleon while it sleeps. I have seen crickets nibbling on a sleeping cham's tail with my own eyes. This is a serious problem for baby chams.
Finally, you will have seen how messy crickets can be in their own enclosures: you don't want them making that much mess in the cham's enclosure too.
So if you decide on the free-range option for your feeder insects (and it is a good option in terms of the excercise and stimulation it provides for the cham), just remember to remove the uneaten insects every night...