He stays in the Middle

Yep thats right my little guy doesnt seem to use his hot hide, in fact Ive only seen him go in it the first few hours I had him. He also never lays on the cool side.Instead he spends all day in a piece of PVC pipe thats in the middle of his cage.

HOT side floor temp is 90
ambient temp is 84
humidity 65

Is there anything I should adjust?

Maybe offer pvc pipe hides on the sides as well, because there's a good chance he's selected this hide as being the most secure choice he has. You don't want him to choose between security and thermoregulation. Sounds like your setup is still working pretty well.