I only plow logging roads so this is only talking about rock, the snow is usually on the wetter side and usually melts before the next snowfall. I like to just skim the rock and plow with the crown. I don't sweat it if a little rock goes with if I can leave the snow on the shoulder where it can be recovered when the snow melts. I play with the moldboard pitch and circle angle to keep the snow moving as conditions change. I like to use at minimum a pitch that will keep the snow from hitting the underside of the circle as it rolls off the top of the blade. I also find that when trying to wipe off a few inches of wet snow, it works good to roll the blade all the way forward and carry the blade at less angle. Let the snow pile up a little more in front and the blade rolled forward will push it down and the pile will do the blading rather than the blade. Works real good on pit run roads so if you hit a rock sticking up, the blade will slide over it easier.