Terry

Herb Malm was the west coast fellow and his system was called NAMSA.... which was decidedly NOT portsmouth. NAMSA used his proprietary algorithm that he would fine tune with race data. Every time he got some race data.... he would recalculate his PN Table.... and presto... your ratings would change. You might remember the large NAMSA handicap table posted at Wroten Point Yacht Club, that was a copy of one of his versions.

In the late 90s... the problem boats were Dart 18s. Darts Like the F16s had two configurations one up main only and two up sloop. Darts were struggling to meet the fleet metrics for US Sailing Portsmouth inclusion since the fleet was more recreational in orientation.... while Herb would happily work with Brian to generate a fair rating since he had his prediction equation. Eventually catamaran clubs decided to switch from NAMSA to US Portmsouth. As you say... cat racing declined rapidly in the 90s and to to move forward and attempt to serve the public, Darline sought other ways to include boats in the tables without all of the criteria required by the PN Standard. So..Darline and the Committee (did my best as did bob) and made the best of the situation to serve the cat racing community.

In 2015, the europeans have the lead in using measurement based system that fine tune the math with race data. SCHRS and Texel. I doubt Oracle is going to solve this problem.
Unlike Herb's NAMSA system... SCHRS and Texel are completely transparent (formulaes are public) and they are managed by a public committee). SCHRS uses English as the base language.

US Portsmouth has decided to return to the letter of the standard. In their view its better to have the tables serve the OD classes that meet the criterion with out compromise. The committee could choose to PHRF estimate the ratings for new designs and include them in the table but is choosing not to. So... if you are racing Hobie 16s against Hobie 18s.... no worries... If you are racing N17s or Carbon20s.... it will be impossible under US Portsmouth.

So... what goes around comes around... Our choice now is a measurement system using a formula tuned with race data!

OR US Portsmouth Somebody will have to champion a fleet of N17s racing other boats including lots of yardsticks to have enough data to get a statistical rating. It may not be an accurate rating however since there are lots of other assumptions made by the PN system that may not be currently valid. (to reprise... garbage in... garbage out)

Bottom line... its time for the US cat fleets to move on.... fleets with the new boats coming to play should plan accordingly.
Part 2,
Sailors who want to improve the OD configuration should just get their stuff measured and use the calculators to generate your specific SCHRS rating.