Sometimes we just need to pay more attention when we set up a snake's cage-it takes practice to come up with new ideas that work, they aren't all the same.
For example, my only super-shy snake is my Korean rat snake, & I just set up his cage with his water bowl in the middle as you described, except that his
warm & cool hides on either side actually have the doorways facing away from the "center courtyard-pool" & are each covered by half of large cardboard box
that surrounds them (filling the dimensions of the tank, open side inward), so each is a cave within a cave, & he feels safe to reach the water bowl from either
side. There is actually more space now for him to cruise his cage (& night when I'm not looking, lol) and he can also use the tops of the box halves*. I may
never see him again? (LOL) but he's obviously happy with it. This is a major re-arrangement of his cage, but it sure didn't stop him from eating, & he's even
shy about that. I don't see much of him anyway...if he's out when I walk in the room, he freezes until I leave, then he takes cover...it's just who he is- wild.
*I also put in a large (5" diameter) cardboard tube that connects the large box halves...a tunnel-bridge. I caught him checking it out right away.
NOT saying you should do this with your ball python...just encouraging you to think more like a snake to figure out what your BP really wants.
Heavy bodied snakes that don't use branches can often benefit from a "2-story" plan...a really large/long hide* that covers most of the floor, & as long as
it's sturdy & not slippery on top (as are most commercial hides- plastic...) it gives them more room to stretch out & use the top too. *That's what I made
for the BCI I had for many years, & she loved it.