.... After owning my GTP I have learned things from him that tells me a water based cage is a terrible idea. My GTP comes down almost every night and crawls all around the cage floor. He will also sometimes coil on the floor and just relax a bit before morning when he takes back to the perches.
Yup, mine exhibit the same behavior. Contrary to popular belief, GTPs do move around. They just don't do it during the day. One of mine can even somewhat regularly be found coiled up under the newspaper substrate. And always spends all of her pre-shed time there.