The schefflera that is commonly called the Hawaiian umbrella tree is safe for sure. Our female veiled has eaten a couple of them.
What kind of Chameleon are you keeping? Some plants are safe to some animals & not others, but one of our panthers has the plant you are concerned about in his cage...
That is quite clever, I use live plants in my cages so working branches around limbs is where I always start. I have a greenhouse & I like messing with plants anyway.
If you use live plants, in larger sized pots, you can sink branches into the soil or strap them to the outside of the pot. If the live plants are small treess, you can attach branches to the trunk. Hope that gives you some ideas. Leo
You can also make a backdrop and leave holes in it to set...