As a data point. Forward CG (by my large self) and full tanks. 2 notches, wallowed around at 33 or so. No break, but pretty solid buffet and descent. Three notches, wallowed around at 30 or so...same deal, no break, but buffett and descent.
And I also use 3 notches under pretty much all conditions. Slower is better, near as I can figure.
Jim