It only calls for an inch of dihedral, and I agree with taking it out. Construction is a little simpler if you do, and I guess rolls will improve, though "wallow" seems a little harsh--but then my standards are certainly not those of an aerobatics columnist! If you're into knife edge then try tip plates that stick down but not up--that should reduce or eliminate the tendency to roll with rudder. Most people just left off the tip plates that come with the kit--they are too small to do anything anyway.

One small correction to the previous post--the airfoil is fully symmetric, not semi.

Jim