Many years ago near the end of the Mug race, I was caught from behind and passed by a Nacra 6.0. I was on my I20, too high a reach for the spinny, he walked by us to leeward.

So, if there is a reaching leg that is too high for the spin, yes, those big old jibs will be faster than the little blade jibs all the spin boats run. But without a B mark, no.