The method i use, i SOAK the vermiculite very much were i never have to add water the entire 60 days. Which is why when using Press n seal and the crate you get condensation due to too much water in the substrate. Thats why you dont need the seal just the lid.
If your using substrateless and press n seal i highly suggest taking off the press n seal. Only need it when the eggs are in the substrate since it cant be too wet. Thats where the press n seal comes in to hold in the moisture due to medium being moist and not wet.