Surface Properties have two rarely noticed options:   Average Normals, which when ON enables... Normal Weight 0% -100%   This seems to control how the surface normal is interpolated from one spline to the next across a patch which affects shading and reflection results.   Notice the difference in reflections and specular highlights in these three images.   From left to right... Normal Weight 0%, 50 %, 100% OFF and 0% is the A:M default but ON and 50% is the result most like the intended
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