Belly heat or back heat?

A while ago I was told that baby ball pythons aren't supposed to be on belly heat, but since then I haven't heard or seen anything about it. Is there any truth to that? If so, what age is it good to switch them onto belly heat? I'm pretty much talking about in a rack set up.

I don't think that's true. But I could be mistaken. As long as your heat source is regulated with a thermostat, which it should be no matter where your heat source is, I would think it would be fine.
I've never heard of that but I'm interested to know as well since you mentioned it. I'm sure someone with more knowledge will reply soon.

heat is heat, doesn't matter. Rack design and the room it is kept is what you need to look at.

Personally I switched all my racks to back heat but I keep my animals in their own room which is warmer than the rest of the house and also keep them in enclosed racks built from 3/4 melamine. So I got about as much heat retention as it gets. If your rack is an open design in a room temp room, back heat probably won't heat the tub enough. I like back heat better as I feel it is easier to make consistent across the rack not having to also travel through substrate. Also the tub just slide up to it and not over it. However Belly heat allows you to use any width heat tape you like which may be necessary if your room is cooler. and also sandwiches the heat between the tub and the shelf which is almost necessary in an open rack design.

Yep, depends on your situation.

I went the extra mile to put belly heat instead of back in my rack. So hopefully belly is the better option lol