For angle of primary scaffolds off the trunk/whip, I have read both 45-60 deg from vertical as well as 45-90 deg. Is it best to aim for a consistent angle out of the trunk (say 60 degrees), or come out at 90 and let it ark up to 60 or 45 as it grows outward?
I am trying to keep most of these smaller - in the 7-10’ range and have a number of young (first and second year) trees I’m training… peach, pear (E & J), cherry (sweet and sour), plum (E & J). Most of these will be trained to open vase, though some modified leader or bush.
Plus it depends on the tree. I have apple trees with a natural strong framework, short branches, and not crazy productive; most training is pruning in order to open up the tree. Others need a lot more attention to avoid future problems.
Which is what you need to visualize, not the sub inch branch in front of you but the 4~5" branch that will become. As the branch fattens on the tight angle literally pushes away from the tree creating a weak spot. Not to mention that the squeeze cracks the bark, letting moisture develop, followed by insects, fungus, and everything else that wants to kill your tree. Future tree health is the most important aspect of training them, better production is a nice add on.