There is no old tired flexible boat discount in any reasonable handicap system.

Put the same rock stars on brand new Tigers and what is your guess at the time difference between this Tiger and a Wildcat in an hour?

It will never happen but my guess is ...that it is not "much faster"

You realize that the precision of these rating schemes is only 1 % (they round the rating off for a reason).

If you had a perfect formula that reflected the small speed difference between a Tiger and a Wildcat...or a Cap 1 and 2 or a F18 and Infusion... it would be rounded off in practical use because the far larger factor in time around the course is the sailor. (Olympic races have spreads of 3 to 5%)

My point being that using a rating with more precision is not going to make the handicap game any fairer or allow handicap racing to manage the differences between F18 Tigers versus F18 Wildcats.

On the other hand... getting an accurate rating is essential! Texel's vetting of their rule by comparing the middle of the fleet times versus Portsmouth's approach of comparing the performance of only the first place boat gets you to an accurate rating system much faster.