I'm all for (voluntary) selective harvest. That said, in any kind of a decent deer herd point restrictions are meaningless, or even counterproductive, in my opinion. In the midwest, at least, a 4 pt on one side restriction just means the up and coming 18 month old bucks are fair game and the lesser ones (from an antler perspective) are protected. I fear this only leads to high-grading of quality (once again speaking from an antler perspective) animals. The only real meaningful restrictions would be an age restriction but absolutely not enforcable and would be a nightmare for a game department. Education of the hunters is the only path forward here. If you want to see meaningful quality enhancement (remember, we're talking antlers) just look at what private landowners are doing - VOLUNTARILY.
Herd control/carrying capacity is a numbers thing - game departments can have an impact on that. Antler quality is a more difficult beast to track down.
The most meaningful impact a state can have on mature deer (that is protecting them to gain maturity) - which, by the way also leads to a healthy herd - is imposing a reasonable gun season that does not coincide with the rut. Just compare IN/MO (long gun seasons, rut) to IL/IA (shorter gun seasons, not in rut).
R