This was one of the knocks against the Tornado in the last Olympic appearance of Multis, that they were NOT one design, specifically in the sail inventory. A lot of time and money was spent by teams developing sails. This led to some crazy out of the box thinking, but wasn't that good from a press perspective (lets not forget the US team's 'code zero' esq kite and how well that worked....).

The T class has worked hard to eliminate this stuff and is now a strict OD (AFAIK), with OD sails now as well. I think they have possitioned themselves well to be the next Olympic boat again.

Nice development track for juniors as well (one example):
Opti (under 15)-> F16 (15 - 18/19) -> F18 (18+)-> Tornado
(example ages and boats)

(I would suspect in places like NA where their never was a huge Tornado fleet even with Olympic status teams would have an F18 here to get into bigger regattas, but maybe not)