We all have our own, interesting in their own right, idiosyncrasies when it comes to this practice, and it certainly cannot be denied that one can pick up any axe and go at it from one side or the other with either left or right hand dominance although this does beg certain questions when talking about an axe with single bevel. But I have to say that I think of this idea of hewing from the but up as a myth that doesn't really make sense, especially in combination with scoring or notching. The idea as I understand it is based on the theoretical notion that the tree is made up of cones stacked one over the other with the outermost cone ending somewhere short of the one proceeding it and so any fractures will follow the rings outward, and at the same time leading to a thicker but and thinner top . This is fine in and of itself but when knots, whorls, twist, reaction wood to name a few, lets say deviations from that idea, are figured in, the practical reveals the myth. Maybe in this instance a forum like this one can be useful in either dispelling such myths or providing some actual grounding of the practice. I've put down my position, probably in an overly emphatic way, but lets call it an initial posture.