Why not just flip your bot over, measure where the blade is before and after you remove the guard.
Negative impacts would be that with the guard OFF the tip of the blade would slice into your toes should you stand in front of the bot and let it run up onto your foot versus the sides of the blade slicing into your foot with the guard ON. Not much difference but it seems to satisfy some folks who worry about those stupid things. Most people know better than to let it run up over your feet, right, so.... your choice