Keith,
Why do Hobie, Prindle, Nacra, etc owners have to "EXPERIMENT" and work all of this spinnaker related stuff out for themselves? I would call it poor product support.
Prior to the I20's use in the Worrell, I went over to the Holiday Inn at Jensen Beach and took a look at the boats. I had never seen so many Rube Goldberg, poorly thought out, spinnaker pole rigs before. Some of those boats needed alot of help. Now most new beach cats have gone to spinnakers and many of the older boats want to upgrade. Why do the factories not come out with well done spinnaker kits for their boats that did not come out with spinnakers in the first place? It would be a source of income. Our beach cat factories and the beach cat sailors would both benefit from well done programs.
As far as satisfactory working geometry goes relative to spinnakers there is a sweet spot fraction on the cantilevered part of the mast for the spinnaker halyard where mast breakage does not occurr. There is a sweet ratio between mast height and spinnaker pole length where the spinnaker tends to lift the bow more than make the boat pitchpole.
Good luck with your spinnaker and your spi pole is too short.
Bill