I agree with dakski's post above- the "humid hide" is in the middle & coincidentally, the temperatures there are also in the middle where he is most comfortable.
Once you get the right temperatures thru-out, you'll find out if he really prefers the "humid" hide or just the temperatures it had. It can be challenging to get
set up for a BP's need for heat, as you said- ..."without the hot side becoming too hot". I think he'll still enjoy the humidity, but will change places more often.