You will probably get a lot of feedback on this. I had a similar problem. I ended up putting in a second UTH with it's own thermostat control and digital thermometer probe for a hot & cool side. Now all is grand in my BP's life.
Good luck.
I have ZooMed thermostat, and a Zilla Thermostat on my two UTH's. The Zilla works a lot better, with a 2-3 degree swing while turning on & off. I notice the ZooMed side can swing about 8 degrees. I am purchasing another Zilla to replace my ZooMed this weekend. From reading a TON of these threads the advice that is issued is that the thermostat is one of the most important items to splurge on, and the online stores have a great selection. But no, the ZooMed will only run one side, not both with different temperatures.