you'd think the manufacturer(s) would want to share polars to sell more boats (which would also reduce the chance of sandbagging for a sweet number).

But yes, comparing foiling vs. non-foiling is even worse than mono- vs. multiuhull.

What did the moth class, and to some extent the A-class, do when their boats started foiling? Did they come up with some handicap or just split the fleets entirely?