Personally, I leave a lot of overlap on the top reed for batwings. I tend to cut back on the overlap when I'm making basic V cut calls. Most V cut calls have to much latex hanging out there for my taste. Gets all muddy sounding, which some like. Some guys call that rasp but it is not imo...just mud. Clipping the corners off makes for a much cleaner turkey rasp for me.
But...batwings...more overlap and I like a heavier top reed for backbone...just me.
Mark