Most chams would not do well in front of groups (they don't like being visible to observers or watched generally). As they are extremely visually oriented they may not "perform" for audiences or shoot at offered prey as they will be too distracted by the strange surroundings and activity. Even very tolerant chams would not like being handed off to someone they don't recognize. Some react to certain clothing colors more than others and how could you predict this anyway?

If you were lucky enough to find an adult panther or veiled cham that is very tolerant maybe. If you raise one yourself there is no guarantee it would develop into a mellow adult. The amount of handling it gets when young doesn't always make a difference.

I have taken several of my adult chams to an occasional classroom show but they were always stressed by it. It could take a day or so for them to return to their normal behavior afterwards. Maybe another option would be to show a video of cham(s) doing their thing rather than have one there in person. You could record their color change display, shooting at prey, closeups of their amazing eye movements, prehensile tails and climbing ability.