Hi Mark,
thank you for your information on your Gonatodes rozei trio and shared picture. To my knowledge your specimens should be originally from Venezuela. I wish you good luck with their breeding even if WC specimens can be sometimes very complicated.
I think that upper humidity value could work well as well as pretty big size of your terrarium. I usually glue cork plates on all three vertical walls of the tank to provide as much space as possible. I would probably separate both females and rotate the male in their tanks, too.
Next your pictures would be would be definitely appreciated I assume that at least 6-8 European breeders keeping more Gonatodes species would like to see them.
Radim