I can tell you from experience that a stone driveway & a snow caster do not mix well together !! I know when you're dealing with feet of snow that you guys are dealing with in the northern midwest, that you need more then a plow on a garden tractor. In those type of snow emergency removals if you have nothing powerful or large enough (Heavy) to do snow removal, keep your blower at least 1-1/2" to 2 inches above the stone driveway, & it will help with not throwing as many stone that can damage your building or buildings, & jamming up the auger blades. I know we all think we can stay on top of changing the direction of the chute as far as damage to the windows, but at a certain point you will get distracted, & in a snap of a finger you'll be saying, " Aw **** " !!
Remember 2" above the stone surface will help a lot, even with the sticky snows !!