No one???? Really???
I see 3 things plugged into that thermostat, I will guess a small heat pad, a larger heat pad and an overhead heat lamp?
You are not properly regulating these. they are not identical and that thermostat is not multi zoned so I know two out of those 3 devices is not running as it should.
The pads are fine the way they are, it would be the same as running back heat BUT it wont be as efficient as belly heat. FYI your snake can burrow and your substrate doesn't need to be that thick anyway.
Your probe should be between the mat and glass, tape is the WORST thing to have inside an enclosure.