Jake,
I guess I told you too much. I explained how the system works and mechanically what effects what relative to sail trim. I did not say or mean to infer that the boat owner has to go through these same experiments to get the straight track self tacking jib system right. The SC and ARC boats with self tacking jib come "correctly tuned" from the factory. These things were worked out prior to 1992 when they became upgrades with spinnakers available on all SC and ARC products.
Some day the self tacking jib system will be common on all multihulls of all sizes, cruiseing and racing and on monohulls also. The system works too good and is too simple to operate to pass up.
I have noticed that boat owners on some Tormados and I20s with curved tracks have added the center pull control line with cleat to set the car postion off boat centerline. To change this line from the trapeze means the crew has to come in off the wire, make the change and get back out on the wire. The automatic self trimming characteristic of the straight track was not recognized by some boat manufacturers.
Bill