Don't think the buffer is necessary in either case but you could certainly use in either. Don't think it'll affect your build so you can get the drums fired up and going then decide when you want to use a defuser.
2004 Weber Performer GREEN
Orange Super-Duper Fast
'08 Weber Genesis Gasser
SJG Tamale Pot Mini Smoker (SJG was a rescue)
and a Pyro FIL