Where did you get that Info that more tumbling gets you more bio-fuel? I would venture to guess that the increased Flow is what gives you more Bio-fuel not the tumbling. But that's JMOIf you notice Mitch, it's really only hefty on one side. Everything else is a subtle tumble, mine is down a notch from this. I would actually slow yours down or keep it the same since adding more tumble encourages more bio-fuel off the pellets, which can cause cyano.
Bill