There's a difference between exfoliating and trimming the sole. Exfoliating is when you stop when you hit live sole. If you scratch it and it looks like a candle wax, you don't cut it. If it looks like drywall and easily scratches with a hoof pick, then it's going to come off anyway. If you use the live sole as a guide, you'll never cut off too much.
Y'all I gotta head for the house. I'll talk to ya tomorrow.
That really makes me think my farrier is trimming out too much. I watch him and he just hacks away.
Have a good evening and talk to you tomorrow!