If you have a standard spin from another class, you could measure that boat.
Supposedly, Performance is changing their sef-tacker to one which resembles the Tiger.

It would be nice if IHCA-NAHCA-PU, would improve the H-20, but that might hurt sales of the Fox, such as they are, HA-HA-HA.
Especially a self-tacking jib to get all of that crew-abusing crap off of the tramp. Yes, I have crewed on an H-20.
They could simply use the Fox spinnaker and sef-tacking jib.
It would take every NAHCA member H-20 sailor complaining to get it changed, maybe.