You left out over 50, 100kg+++ on yellow, hand-made Australian boards.

Confining the thinking to racing - gradings make sense in the long run...if & when we get the numbers up and a history of race results. Would only need A,B,C & maybe D. Get 30-40 paddlers on the day and there's a field in every grade.

. With gradings, the mere mortals who will never be quick (no matter how many concrete smoothies chugged), for reasons of physiology, age, previous lifestyle choices, adult jobs & concomitant lack of water time etc, etc, etc, get a race that means something. And the elites get their race too. So does everyone in between.
You know it makes sense, even if I'm not Sam Kekovitch.