I've been doing some thinking, and sculpting some complicated shapes on SP, and I got an idea. What if we could have these two features, concave corners and adjustable corner radius? What I was sculpting for hours would be done in mere minutes, with far fewer parts, and it would look a lot better.
With current fuselage customizations, we can't get this kind of shape:
We also need to keep the entire part colored red in the picture above. And we have no reasonable way to make modern aircraft cross sections, such as this:
Radius editing would be such that the curve takes a certain percentage of the side of the fuselage block (default 50%) for circular corners, and exact radius of the corner curvature for round corners.
All illustrations by me