Hi Alan
The SAKITUMI was inspired by three un-flapped designs; the Primary Force, the Doctor, and the TEOSAWKI. I always thought that the TEOSAWKI was a great design. It is particularly sad that no kit or ARF is any longer available. I used a TEOSAWKI and Primary Force for nearly 3 years and they helped me learn the pattern as well as win a number of contests. I retired my TEOSAWKI this year in memory of its designer, the late Clayton Smith who I have huge respect for, he designed and popularized a very clever design.
The SAKITUMI was designed to take the best of the unflapped planes I had flown and make a really great practice and intermediate plane. What I was really surprised by when I first flew it was how outstanding its performance was. If you were able to pick up the handle without knowledge that it didn't have flaps and fly it for the first time you wouldn't know it is a flapless design, it performs that well.
RE Design; I have worked on a few designs, the Cardinal Evolution is probably the most famous one I designed with Windy Urtnowski at my kitchen table 11+ years ago.
I didn't work completely alone on the design and drafting. John Miller was outstanding in his help with the early CAD drawings and his suggestion of a very effective airfoil was important, the design has a thick very forward high point airfoil, it is similar to the shape of full size Aerobatic planes airfoil. (Maybe John can add details here?)
The great things about profiles even for advanced and expert flyers is that they have a higher "expendability quotient", you feel like you have less invested in them as they don't take long to build, I believe this is why even simpler unflapped planes have a place in a more relaxed flying experience (at least for me).
RE the molded LE; Balsa molding can be very simple as long as you know to soak the wood thoroughly and I hear so many flyers say they cant make it work that the simplest tip I know is just "soak it a'while". Balsa really doesn't need 24 hours of soaking but I have found that if the wood is soaked cold it usually needs longer, and soaking longer also lowers the risks of splitting in my experience. The kit is designed to use a conventional leading-edge but there is no reason why you shouldn't mold one and have the effectiveness of a very consistent leading-edge shape just like the prototypes. The LE is in fact very blunt and not tight in radius at all.
Yes it is an inline design, I have no idea if it should work, it just does. I have read all the pluses and minuses on inline setups, all I know is that it works on this design with the light landing gear and an LA 46. Lighter or heavier engines, bigger or heavier wheels might well change that.
Overall I am very happy with the SAKITUMI, I hope a few other folks get to enjoy one.
Eliott