I know my draw knife well. I keep it sharp. Whether I use it bevel up or down depends on what I need from it... just like flipping over a farrier's rasp as needed, or keeping different size curls on my scraper and flipping it as needed. 'Right' is what works best for the task at hand.
When I'm hogging off bark, sapwood, and blasting down through heartwood, pulling off long and thick curls, it's usually done bevel up. When I need to use finess, chase a thin ring, work around knots, etc. I usually run it bevel down, often using tool angle and the bevel itself as a depth stop.