Cut the plant so your cham can have a basking spot unless it has a good basking spot on your plant. I would cut the plant so there is around a 6 inch gap from plant to the top of the cage.
What I'm gonna say is gonna sound pretty obvious but its true... Chams live in trees and heavy foliage... I wouldn't say there is a problem unless he can't bask and can't find food.. To ensure food consumption I would recommend cup feeding but thats JMHO... I have a schefflera that covers the entire bottom and 1)it helps drainage issues... 2) gives him WAY more patrolling ground... and 3) gives him plenty of perches... I think its good not bad