Hi,
Temps are sounding good. :gj:
I would double check what they are on the glass at the hot end under the substrate just to make certain he wouldn't get hurt if he burrowed down ( if it does turn out to be too hot the simple solution is to use less substrate so the heater doesn't have to work as hard to get the in hide temps spot on :) ).
If the wrinkles haven't gone away yet I would actually think about soaking him again for 30 minutes or so - remember to keep the water temp around 84-86f so it isn't too hot for the lil guy.
As long as the water is only half way up his body it shouldn't do him any harm and might help re-hydrate him a little bit more.
Unless anyone else has some other ideas to try first?
dr del