I think if you lava rock'd a weberQ you would get what you're after - kinda.Same here. I hadn't tried smoked meat before. Got a Bullseye and have tried numerous flavored pellets. Haven't liked any of my cooks. I wish lava rock gassers would make a comeback.
I have one of the portables - it has a single tube oval burner at the bottom. (NASCAR Track shape?)
Never thought about lava rock until you brought it up.