I use 2 identical pieces of flexwatt, essentially 2 identical UTHs, one on warm side one on cool side.

I have the warm side connected thru a ZooMed 500R thermostat set to 90-94. The cool side is connected to the same thermostat but with a dimmer on the cool side UTH adjusted so the cool side gets to 80-84 This way I can have 2 different temp UTHs controlled by 1 thermostat.