Are you still planning on going ahead with the yawl plan? I'm following this thread closely as I'm interested in doing something similar. I'm also considering a gunter rigged yawl with a self tending jib. I know that adds the complexity of a stayed mast, but you gain pointing ability over a lugged yawl.
You mentioned earlier in this thread that you calculated CE for the new sailplan. Did it change your foremast location? It looks like you kept the off-center centerboard installation as designed, with the yawl rig, couldn't you have put it back on center or are you just keeping your options open? I assume that the reason for it being off center was because of the ketch rig mast location, but I don't know.
Right now I'm researching a build and trying to decide on whether or not a modified CS is right for me or if I want to try my own design (I doubt I could do better than a CS though). Alan S pointed me this thread in an email exchange a few weeks back.
