thats a very very good sign he is eating more with more humidity! make sure you give the humidifier a day off here and there to reduce risk of RI. if he's an active and not skittish frill then you will be ok with following a regular care sheet of 75 at night, some frills dont do well with the lower temps advised because they are more flight and fight then calm and seek heat you knowo what i mean? hence why i said body temp of 95.
post some more pix up of the lovely frill!!!