I have the same enclosure and keep two sheets of newspaper on the bottom. If it's staying in the mid 80s in the center of the cage then wet news paper should dry out fairly quickly and is easy to replace when it gets soiled by the cham, as long as you don't set plant pots on it. I'd be a bit worried about too much moisture and mold sitting between that mat you have and the hard bottom.
I'm not positive whether your live plant is pothos (Epipremnum aureum) or heart leaved Philodendron, but I would remove it if it is philodendron, they're in the Araceae family and contain calcium oxalate crystals that can burn. I'd replace it with some pothos and draceana, both non-toxic. Other than that, I would say add a lot more vines and sticks (chameleon highways) and hanging plants like you have, to help break up the tank more and give the cham more security, my friends can stand in front of mine for minutes without finding the cham in it.
I can't tell from the pic if it's a male or female, but if it doesn't have a spur on the back of each hind foot, it's a female and you'll want to add a sand bed for her to release eggs in if she needs to, or else she can become egg bound and die. I use a kritter keeper with about 8 inches of sand and keep it firm by moistening it during mists. They can produce infertile eggs like chickens, but I've kept my female from producing any, you can do that when yours gets older by limiting her food to about 20 insects a week, divided up daily or every other day.
I use a spray bottle sometimes too, but eventually you will probably want to get one of those fertilizer/insect spray pressurized sprayers with the pump on the top, from home depot or walmart, then you can just pump a few times and clip the handle together to mist rather than pumping a regular spray bottle with your fist a hundred+ times at every misting.