Ok, so OP....
Yes, that is sufficient space to house your BP comfortably.
Also, yes, your BP would probably use more space if more space was provided.

This is where it comes down to what works best for you AND the animal. As you can see throughout this thread, there are differing opinions and no clear "RIGHT" way of doing things.

So, my two cents is this:
Will the animal have room to move around and find the temperature gradient needed?
Will the animal feel secure?
Is the enclosure escape proof?
As long as you can maintain proper husbandry and the animal is living a safe, healthy life, I say use that enclosure if it's what works best for you while still providing the proper husbandry for your snake.