Hello. I've read a bunch of threads about opening the wood tray to allow more air in the MES 30 so the AMNPS works better but has anyone had success with the 30" Analog model? There is no external wood tray or vent adjustment. I'm also wondering if anyone has built a "roof" so droppings don't smother the pettets? I've made the foil tent but would like to do something more permanent. Thanks in advance.