The language in the IHCA rules for all the boats (with the exception of the 14 and 16) states:
1. RUDDER BLADES AND RUDDER ASSEMBLIES
1.1 Rudder blades and rudder assemblies shall be
stock as supplied by the HOBIE CAT CO.
1.2 HOBIE CAT CO. supplied rudder assemblies
and rudder blades shall not be modified except
for minimum filing to improve fit and function.
So . . . technically, EPO's are not allowed on the 17 and 18, either, although every racer I know uses them.
And modifying them to fit the EZ-Loc system isn't legal either.
(The 14 and 16 have allowed aftermarket rudders since the early '70s, when racers demanded a better blade than the ABS ones originally produced for the 14.)
