For those of you who have experience, would you feel comfortable placing the vent at the back of the vivarium's lid
Late to the party here, but this is all I do, except when I've got the whole
top in screen. I water the hell out of my stuff and get a ton of evapo-transpiration. I drain everything too, but actually get little leachate.
Important detail - the environment outside here is very dry - about 16" precip/yr, about a third to quarter of potential ET. (That giant sucking sound is the atmosphere taking everybody's water.) My herp room feels pretty humid, but the air is still really thirsty.