Ah, I've been beaten to the response...by my own posts! Thanks, Del.

But yes, the point of the cover on the back and sides isn't just looks, but also insulation. A background of some type not only looks nice, but prevents the snake from seeing the reflection of things moving by the back of the tank. It also, as was said, allows the insulation to be added and not affect the look of the tank.

My first BP was only 2 months old when I got her and I started her in a 20gal long tank that was 'cluttered' with greenery and hides. She loved it. Each snake has their own preferences, and if yours is doing fine in a larger tank and isn't always frantically trying to get out, then it's all good.

A note on feeding in another container - you said you did it because of the substrate, and you shouldn't worry about that. Snakes can digest fur and bones, so a little piece of shaved aspen isn't going to hurt them (unless they get it stuck somewhere). If you're really worried, put a piece of cardboard over the aspen before you offer the prey.

Anyway, good luck getting everything working to your liking! If you have any questions, feel free to ask!