Been a BP owner a whopping 1 month, and I'm still trying to dial in my setup...

With temps dropping here in CT, I realized I'll need an additional heat source to keep up the temps in my BP's enclosure for the winter. The room in which he's housed stays around 68 degrees during the winter, so I went with a 60W CHE (it's a small enclosure) on a dimmer + a Hydrofarm thermostat.

Here my problem: in order to maintain ambient temps of 77+ (it's set to 79 degrees on the cool side), the CHE is turned on a good amount of the time. I recently measured my surface temps now that I picked up an IR temp gun, and they were 100+ on the cool side (under the CHE) . Obviously since I discovered this, I have turned down the CHE with the dimmer and moved it farther away from the enclosure (i.e., raised it up). Surface temps on the cool side are currently about 86 when the CHE is on and ambient is hovering around 76.

Is this OK? I can't really figure out any other way to maintain ambient temps without cooking the surfaces beneath it.
Suggestions?

Here's the current setup for reference: basic tub, 2 hides, UTH on hot side, CHE on cool side, 2 thermostats, water bowl


I'm trying not to overthink this and worry about it too much. And my BP is eating regularly, poops/pees like a champ, and has had two good sheds. I assume he is no worse for the wear, but I obviously would like to take the best care of him as possible.