The reason why the 404 brake rub is the 20 rear spokes. That not enough for what is a very stiff rim. 4 more would solve the problem.
Stiff wheels can be co.fortae. it highly desirable for wheel to be stiff. In fact it's the spokes have to impart sufficent stiffness to stop the rim from from bending . The stiffer the rim the more the spoke have to do.
Discuss light weight issues concerning road bikes & parts.