I've adjusted the heat mat's thermostat already, turned it down to 89 degrees since it likes to get a degree or so higher than the set temperature before shutting off.

If you don't mind me asking, how would I go about regulating the CHE with a thermostat? As in, where would I put the probe? I'm not exactly sure how I'd set that up so that the CHE didn't get too hot or cause heat spikes.