I don't know exactly what your seatpost setup is, but the MacGyver method of making a seatpost clamp micro-adjustable is to shim the serrated part with a piece of metal cut from a can. I've had the best luck with steel (aluminum is too soft and compresses pretty quickly) folded over once to make a double thickness. It takes a little fiddling, but it can be done. Use snips to cut it and pliers to fold it (so you don't cut yourself).

Still, a micro-adjustable seatpost sure is nice, and between that and your issue with setback, I guess it depends on your budget.