would a dimpled heat shield reduce heat transfer during reentry? Would a large ceramic golfball absorb less heat on reentry than a standard sphere?

"The difference in the flowfields around a smooth sphere and a rough, or dimpled, sphere can be seen above. Since the laminar boundary layer around the smooth sphere separates so rapidly, it creates a very large wake over the entire rear face. This large wake maximizes the region of low pressure and, therefore, results in the maximum difference in pressure between the front and rear faces. As we have seen, this difference creates a large drag like that seen below the transition Reynolds number"(http://www.aerospaceweb.org/question/aerodynamics/q0215.shtml).

Would the reduction in heat absorbed be significant enough to warrant a larger payload via lessening the weight of the heat shield?
Near as I know, the key to designing good re-entry vehicles or shielding is large flat plates, primarily because the design ensures the energy transfer from kinetic and potential energy of the craft to thermal energy  occurs mostly in heating the air flowing around the shape rather than the craft itself.  It sounds kind of counter intuitive, but doing this ensures the spacecraft remains as cool as possible and the least risk to structural damage from heating exists.  Therefore reducing drag is these applications is not a top priority.