The self-righting property would be completely unaffected if the surface imperfection is smaller than a certain threshold value. This value is a function of the

The self-righting property would be completely unaffected if the surface imperfection is smaller than a certain threshold value. This value is a function of the "equilibrium-ity" for any point of the surface. Close to the stable and unstable equilibrium points, any imperfections create additional equilibrium points, like someone else mentioned. The threshold will grow with the distance to equilibrium points, so in some places, an eye lash, a grain of sand or the inscribed logo makes absolutely no difference.