I've built three small boats in the past five years, all with daggerboard variations from the norm. The first was my pram "Matins". I was given plans from my son in law and was a total neophyte to the craft. The plans called for the daggerboard to be right in the middle of the midship thwart. Since that was about the only place for a passenger to sit I did some research on the balance of Center of Effort and Center of Lateral Resistance and decided that I could move the daggerboard forward, but have it slant back to move the CLR toward the planned position (pic attached). It has worked out pretty well thus far.
I also built an OSB with my Grandson and incorporated the design of a PDR center daggerboard into it. Not unusual other than the OSB plans were for a row boat and not a sailboat. It sailed well, but performed more like a sailing canoe than a sailboat.
Finally, I made a PDRacer for my wife. One of her specifications was that she have ample room to carry Grandkids. After more research online I discovered an Oz PDR that had the daggerboard in the side air box. I engineered her PDR to that end. I used plans I bought online, but modified them considerably as the plans called for a traditional center located daggerboard box. As it is the box is encased in the starboard air box and is both easy to use and leaves the cabin of the PDR completely open. After tuning the rigging she sails like she has an outboard motor attached.
