I personally don't think that is an appropriate way to keep a ball python. It is not so much space as it is heat, humidity and security requirements. What you take to mean exploring or enjoying the enclosure is a sign of stress. A happy ball python is a hiding ball python. They need to be in an enclosure where they can completely hide from you, they are not display animals. You have already been told what you need to fix, so I won't elaborate.
Your snake could be small because of the amount of calories the poor thing has to burn to get around that enclosure. Ball pythons are very inactive, heavy bodied snakes. They are not built to move, and their metabolisms are not designed for much activity. The most movement your snake should have to do is a short slither between warm and cool hides.
I understand that you like your enclosure, but you are just keeping the wrong animal in it. With a lot of research, you may be able to make that work with some type of arboreal species like a green tree python or emerald tree boa. Those are considered DISPLAY animals. They are not known for being friendly, you don't take them out and hold them. You put them in beautiful elaborate enclosures and admire them. That's not a ball python. A BP is a great snake to take out and hold while you watch TV, but it needs to be hidden away the rest of the time.
I commend you for coming here willing to learn what you need to do for your snake. There are a lot of people who never do and their animals suffer for it. I seriously suggest starting from scratch and getting your snake in a tub with two hides and an under tank heater with a thermostat. It will thank you for it.