The only thing I will say is that there is a great deal of difference between a "trophy" deer and a "mature" deer. Trophies aren't everywhere for the reason you described. Mature deer on the other hand are a possibility anywhere deer are located. Mature deer are mature deer, regardless of genetics, supplemental feeding, etc. I would never suggest that a hunter only hunt for "trophy" deer, all I would like to see is hunters actually "hunting" (ie. spend some time looking) for mature deer.

By the time a buck has reached 3 1/2 - 4 1/2 years its overall antler characteristics aren't going to change much. At this point the hunter can make an educated decision as to the deers potential or lack of potential.