I received my set of plans as well, but I have a computer build on the bench and haven't opened them up yet. I'm not planning on building one, but it will be neat to see the drawings.

I'm not a boat designer by any stretch, but I have a feeling some of the magic of the Thistle comes from what Sandy said here:

“Now we come to the lines, the actual shape of the hull. With the greater length
and beam we find that the displacement has come up rapidly so that we can ease
the lines quite a bit as compared with the International 14 which has to be pretty
chunky. Then a compromise. We want firm bilges to give stability, but if they are
too firm she will have too much wetted surface, which will make her sluggish and
sticky in light weather. Suppose we see what happens if we put the fullness of the
bilge just above the waterline. This cuts down the wetted surface greatly, yet the
power is there as soon as she heels a little and the big bilge sinks into the water.
She may seem a little tender at the dock, but once underway she will stiffen like a
house."

This might be why she is so slippery in light airs and still feels a bit tender when single-handed. With one aboard there might not be enough ballast to settle on the bilges.