An unregulated heat pad is an extremely bad idea! For whatever reason it seems to get even hotter when attached to a sheet of metal then if it was just placed under a tub by itself. I often times don't take advice so I usually learn things the hard way and I can tell you for a fact that a little 10 gallon UTH on a 41qt sterilite will over heat the area that it's attached too. If unregulated by a dimmer switch or thermostat it can and will be too hot and not possible to control. I've also had a giant sized one attached to a sheet of glass that was in the snake condo I bought and at first I transitioned it to the top of my rack system and found during testing that it got both tubs on it hot enough to burn my hand. As far as shedding recommendation... I have used about every one you can get at petco and petsmart and they have all worked great for me depending on where I place them. During shedding I will have 70 percent humidity give or take 5 percent. I also pay attention to the temps too because high humidity and low temps are more prone to give RI from my understanding. Even though all my Ball Pythons are housed identically I do have one that seems to have a tiny bit of shedding issues and I use on him what I use on my chameleons which is the shedding aide you can get at most pet stores and it's worked to help with a few issues.