from my readings, yes they're okay but do need some adjustment to help trap humidity. so far i have not made adjustments to my 12x12x18 mesh top and it's doing well, tho it does get close to dropping below 50% if i don't pay attention. i'll be adding tin foil over one half in the next day or two.
crestie enclosures should be misted once or twice a day to jump that humidity to around 70-80%, then you allow it to fall throughout the day/night (not dropping below 50%).