Terry,

I am going to be the heretic here.
I have been thinking about a kayak based sail design myself.
You need to put about 1" of forefoot and 1" of stern in the water.
To do that you need to add rocker, then calculate the displacement and compare it to the total weight you expect while sailing.
Since you will have decreased the volume on the original design waterline and increased the weight due to sailing equipment, you will have to see where the new waterline is. Then increase the rocker to get the forefoot and stern depth again.
Repeat until you get minimal change in depth when you changed the rocker.

A note: your kayak will not be very good as a kayak now. just as it was not a very good sailboat to start.
Tracking as a sailboat is primarily a function of the centerboard/ leeboard and rudder. So those need to be big enough to overcome the lack of tracking in the hull. Note again that when you go to kayak you won't have much in the way of tracking.

I believe you need to decide clearly what you want - a sailboat or a kayak.

Since this is a SOF you might be able to build it to sail (plenty of rocker), then use some cables under the gunwales to bend it down at the bow and stern to take out rocker for kayaking (removing the rocker by force). It shouldn't take much force, SOFs bend fairly easily. The attachment for the cables may be highly loaded.

Personally I am worried about the sail and mast forces in a SOF. I've never decided how to handle those. But of course I want too much sail - not just a postage stamp.

Kukzu was talking about a Trimaran SOF sailboat. You might talk to him. I don't think he figured out how to handle the loads to his satisfaction.