The wedge shaped sponson doesn't provide the support needed to the front of the hull and will allow the forks to go under the water and turn your boat into a submarine when you slow down or turn. A sponson can have a series of wedges (shingles) from front to rear and that kind of works but that arrangement gets complicated and tends to be very hooky and unpredictable in the turns due to a variety of hydrodynamic downfalls. I tried all that years ago and it produced nothing positive. The best arrangement for an outboard tunnel (to this point at least) has been the smooth radial bottom design. It's a trade off just like everything else on a tunnel boat but is works well. That flat plane technology that is the rave these days works great on a hydro but it is not the direction to go for a tunnel boat in my opinion.
There are some saying that if done right it will work and all but nobody has produced a shingled bottom outboard tunnel boat that has impressed me yet. If you are truly thinking of designing something that will be competitive with today's designs, don't get far off the path of what is working now and try to make improvements from there. I will tell you that improvements will be small but they are there to find. I have just released one of my newest designs " the Taboo" and it does not have wedges, steps or shingles on the sponsons and it has very nice characteristics at more than acceptable speeds.
For example, the newest production design in my shop (the boat that will one day replace the recently released Taboo) does not have stepped sponsons on it either. When I release a model to production I already have the next design ready to go but someone will have to build something to outperform the Taboo before that design leaves here.
My point is, wedges or steps on your sponsons are probably not going to produce a truly competitive round track outboard tunnel boat.
-Carl