You mean more "post" than the sense coils? I could quite easily design a servo with a lot more loop gain than the usual ones, but beyond that I think that the difference in shape between the playback and cutting styli will become the more fundamental problem.
Actually I tried starting such a project but I was held up by other stuff. By the time I was ready to characterise and model the loaner cutting head the owner needed it back (on account of having fried another one). I should pick it up again.