I have a few things I'd like to say to your enclosure:
1. "He just ate so I don’t wanna mess with him, but Monty seems to be happy in this rather large terrarium."
--> It's a great sign that he ate. A happy snake is an eating snake. By the way some snakes just prefer larger enclosures. Mine does too. They all have their very own character. I also really like the name Monty.
2. "Hot side is 85-80, cold side is 79-73, heat mat under volcano (hot side) so he’s very comfortable."
--> The hot side should be between 89 and 92 and the cold side should be between 77 and 80. It might be a little too cold in there. Do you use a thermostat?
3. I wouldn't use a log as a hiding spot. They are known to be quite bad for ball pythons. In my opinion it's best to choose two identical hides so that the snake doesn't choose security over thermoregulating.
4. I would also use a digital hygrometer and thermometer. They're more precise.
5. Is the rope really secure? Ball pythons love to climb but that doesn't mean they're the best at it. I feel like a rope is just asking for an accident. Maybe choose a big branch that doesn't wobble as much as the rope. It'll keep your snake safe.
Otherwise the enclosure looks fine to me
By the way, you're one of the few people I've seen that didn't start of using Aspen.