I'm a little late to this discussion but my thought is this, get your basking dialed in and don't worry about the cool side as much. Your dragon is going to go to the temp it likes best. As long as the cool side is above 70 or so he will be ok. I the wild they move in and out of the sun as need to maintain the desired body temp. They will do so in captivity as well. He might actually appreciate having a place in the low 70's to cool down.
I'm a little late to this discussion but my thought is this, get your basking dialed in and don't worry about the cool side as much. Your dragon is going to go to the temp it likes best. As long as the cool side is above 70 or so he will be ok. I the wild they move in and out of the sun as need to maintain the desired body temp. They will do so in captivity as well. He might actually appreciate having a place in the low 70's to cool down.
I never really bothered worrying about cool side either. I just wanted to make sure that the air temps I'm getting throughout my enclosure just to keep surface temp in basking site warm enough were ok. Wasn't sure if temp gradiant of 90 on warm side to 80 on cool side were to warm or not. Air temps do go down as day progresses and temp inside house cools off.