Finally got my stuff together. I'm currently running the thermostat and heat pad in the empty enclosure just to test the probe/thermometers, etc and get a feel for where I need to set things.

The thermostat is a herpstat. I currently have it set to 87.0F. The probe reads 87.1F and seems to spend a lot of time at 0% and coming on a little bit to warm it about 0.4F above 87.0...

The thermometer reads 85.5F

Temp gun reads 86.1F

The thermostat probe is glue-gunned very securely inside the enclosure (I did read into thermostat placement, risks, and reasons... This wasn't a 'didn't know better' decision. There will be a backup outside of the enclosure, and the probe inside the enclosure was secured as if it was my own face that was going to be lying on it).

So I understand that there's going to be some variance between temperature readings from different probes on different equipment, so do I trust the herpstat probe more than the temp gun?

The enclosure is not set up as it will be (no substrate, hides, etc). I'm just trying to get a feel for my equipment with an arbitrary temperature, first.