That's true about the scoring angles, however this is what happens sometimes when a right handed guy uses a left handed axe! In my experience, you can make it work out if you pay close attention to your strokes.
As for using a rounded axe to score, they certainly did in the old days. In the regions where juggling was done with a felling axe, that same (rounded bit) felling axe was often used to score the face before finishing with the broadaxe. This can certainly be accomplished with fine results if you make a series of shallow, staggered scoring marks rather closely spaced. I like to use the broadaxe for this sometimes because it is so wide, and close to straight, but I've never really had any trouble with a regular felling axe.
http://www.en.charpentiers.culture.fr/treesintohouses/fromtheforesttotheworksite/squaringoffGerman hewing, and check out all of the other videos there too, and most importantly LEARN from them!
