In my opinion there is no reason to change the cloth weight for OD racing - 3/4 oz is equally good or bad for all (only the sailmakers will gain).
For boats sailing PHRF it is always an option to use a 1/2 oz and most likely the rating penalty coming with it - don't kid yourselves thinking the J/30 rating will stay the same just because we changed the class rules.
If it's decided to allow 1/2 oz there should be no restrictions - we should be allowed to use 2 spinnakers for any event (spinn #2 should be optional as Genoa #2).
Bengt Johansson - "Fuzzy Wuzzy"