i want to switch to using a tub for my bp but understand that the cool side will heat to the temp of the room. would i be able to use two uth and two thermostats one to set around 80 and one around 90?
Don't see why not, but most room temp is not to cool for a bp's cool side... unless you are just not heating your house at all and you live somewhere cold.
Just get some heat tape or a UTH and a proportional thermostat; place the heat tape/UTH under the cool side and set the thermostat a couple of degrees higher than you target temperature. The python will still be able to regulate its body temperature just fine with a single heat pad, and you don't have to worry about it overheating since the one side doesn't have a heater.
Should be fine, I have my balls in a rack, and the warm side is set to be 94, and the cool side ends up around 80. Though it never hurts to add some back up systems.