Creating slots in the biscuit for the fletching to pass through will also compromise some of the arrow centering attributes of the rest and lessen its reliability. I would not do it. On a tuned bow the old black biscuit might have cost a couple FPS and some minor fletching wear. I'm not seeing any speed loss or fletching wear with the B-2 biscuit and don't even advocate trimming with the B-2.

Good luck hunting!