I'm not an expert, but I'm concerned about the shapes. The hull is very boxy, with almost no rocker, and and the coaming is D shaped, which will make it really hard for the spray skirt to seal. I'm wondering if he's decided to design it this way because he thinks it will be easier to build if the shape is less complex, and that this is influencing the design more than the completed boat's on-water performance.

I think the shape is a bit unusual. There's an illustration in Nick Schade's book of a hull shape like this with some suggestions on why it might not be ideal. But- it depends on how he intends to use the boat. Every boat is a compromise.

Before committing the design to 3D it wouldn't hurt to look at the lines drawings of pre-designed boats with proven performance characteristics. Guillemot and Bjorn Thomasson are good places to start.

At least with a SOF you can make changes after the saran-wrap test, or in this case since it's a new design, he could skin it in something really inexpensive like clear vinyl and paddle it for a bit, then make changes and reskin if he doesn't like it.

best of luck!

m