You should learn to cut your leather off the edge of the bench. I was taught that many years ago by a good saddlemaker and my round knife edge hasn't touched anything but leather since. It takes a little practice but you'll soon teach yourself how to do it. Leave what you're cutting hanging over the edge. Your knife will stay sharper for so much longer and believe me, you'll soon shudder at the sight of someone using a razor sharp round knife to cut into their bench, poundo board, or anything else.