I did some digging and may have answered my own question.
I upped the temps a few degrees this morning. I went from 75F on the basking spot to about 79F on the basking spot. The tank overall warmed up a couple of degrees. I'll see if this stimulates him to eat his gel.
I can go up to about 81-82F comfortably with him and still a few degrees of margin of error. Chewie's can go to about 85F in the summer, but not much more. I believe Leachies are a little more sensitive. Ezzy is about 75F all year round and eats like a pig.
I have also upped humidity recently for both Rhacos. That seemed to have little effect on Ferry.