We dropped the fletching size requirements because it added complexity to the rules, was inconsistent between bow types, and often required that an archer refletch their regular hunting arrows just so they could compete. In other words, the fletching size rules didn’t make a better competition so it was dropped. Besides, fletching size is self regulating because too small, and the arrow Flight suffers. Too big, and there is excessive drag on the arrow. Just like regular hunting arrows, each Broadhead Flight setup is up to the archer to optimize for performance.
Alan