I have a juvie bp and my setup is as follows-
40 gallon terrarium with a plastic hinged locking lid, which has a middle metal screen portion where I have a 75 watt CHE, hooked to a thermostat set at 80, with the probe down inside at just above floor level on the hot side. The screen portion of the lid has aluminum foil over it except for a 1" ring around the CHE dome. (I should also mention that this particular terrarium has an airstrip for ventilation on one side of the tank.)
I have an UTH hooked to a thermostat set at 95, which gives a digital thermometer readout of 89 directly on the glass under the warm hide.
My substrate is coco block with a little reptichip mixed in. I also have several branches and an aloe plant in the tank to clutter it up, a large water dish on the cool side, and 3 hides of different sizes throughout the tank. The back of the tank also is blacked out (sort of. Its a jungle scene).
My ambient stays 78-80 with this setup. My room gets about 79 during the summer afternoons (Florida), so the CHE really only comes on at night or in the winter.
My bp is around the same age as yours and was very nervous and defensive when I got him home. With this setup, he has never refused a meal, sheds perfectly and has quieted down to puppy dog tame with minimal handling.
Sorry for the long post. Just wanted to share since we have similar snakes and setups. This has worked well for me.
Sent from my LM-X220 using Tapatalk