John, you didn't indicate a point of sail. My notes say point at the shroud when sailing upwind in light, medium and heavy breeze. Downwind: 90 to 100 degrees in light to medium breeze and 70 to 80 degrees in heavier air. But then you're sailing with an entirely different rig, an SX mast with a custom flattop sail. I suspect your sweet spots are going to be different. Is your SX stick solid aluminum or does it have a comp-tip? What are you using as a Portsmouth number for that rig?
'82 Hobie 18 SE with '85 Nationals Prism (White) sails
'73 Laser HID# 3463