No idea how AP cages work and how much they weigh. So moving later could be annoying, no idea.
My guess is that flexwatt with a thermostat won't get hot enough to hurt anything, but maybe put a piece of plywood/PVC, etc, to buffer the floor just in case?
Also, going to be a royal pain to clean when on the floor.
My Boaphile setup is 5 tanks high and they are on a 12 inch stand/box. I use knee pads to clean the bottom tank where Figment, my Corn lives. It's only a foot off the ground!
Be careful spraying often, it can cool the temps a little, even with warm water. I try to do once a day or every other day, at the most, even if I spray more in one shot.
With your new cage, I imagine it's going to be way better.