Jmoney, I like your idea of a ball valve on the intake instead of the slides. The slide on my vault has a very loose fit and it's pretty difficult to fine tune running a dry pan. It will go through a rack of fuel in about 6 hours with water and is difficult to keep below about 300 because of all the inlet air and draft on top if running dry. I wrap the slide in foil and use a guru sometimes. Valve is really good idea.
LBGE, Traeger 075, Pitmaker Vault on LT-1 Trailer