There is a problem with the subdivision, the middle point subdivision algorithm, no matter how much you subdivide, will not make a sphere or cylinder's contour more round, it will render the same as it was before the subdivision.
It is useful only for improving the deformers' (magnets) amd bending precision.
The explanation is that a quad or polygon is a flat surface, if you subdivide a quad you will have four smaller quads that all are flat and belonging to the same plane. If you subdivide again you will have 16 quads, but these 16 quads will be in the same plane and so, the original polygon will continue to be flat no matter how much you subdivide.

Catmull-Clark or loop subdivision produces rounder objects, but it destroys the original curvature.
I experimented it and the result was horrible, I think that for toons it will work fine.
Something else must be used, something like a modified middle-point subdivision that takes into account local curvatures and its continuity. I don't know what can be.

Stupidity also evolves!