we see some 10pt 1.5yr olds....so that makes me think as long as they've had good nutrition they'll show their potential, or genetic frame early on, but who knows later on they may become a main frame 12...
we also see some 9 or 10pt 1.5yo...some 8pt.
If you really wanted to experiment you could pass all 10pointers you see, and only havest the 8points, especially the younger ones, as a study I read suggested overwhelmingly that the younger bucks are doing the majority of the breeding, ie 2.5yo and under...
its hard to say though.