Excellent posts, Baker. About the only parts I'd somewhat disagree with is that there is no reason to remove bucks before 4.5. I've lost way too many stud 3.5s (150+) to neighbors that the evidence pointed pretty clearly to being driven out by 4.5+s. When I hammer the low end 3.5s, it doesn't happen anywhere near as much (still happens, but much reduced level), as there aren't as many 4.5+s and more potential holes . No, other 3.5s are rarely pushing them out, but if you don't start removing at 3.5 you're likely to be too late. It's too tough to get the lower end 4.5s out before the push begins (in the Midwest and points north, mid Oct). So, the 3.5s that were removed in 2015 won't be there in 2016 to nudge 2016's 3.5s to their demise at the neighbors' hands. At the same time, it also reduces social stress levels, something that I see as not given anywhere near the importance level it deserves.
If I were managing a high fence, I very well might wait until 4.5 to put them on the hit list, as they can't drive other bucks to the neighbors, but feel that's a year too late on the larger, free range properties I use this method on. I've never managed a high fence. So, I'll certainly differ to your experience on that.
The other area that I agree, yet respectfully partially disagree is that one has absolutely no clue what bucks will and won't do year to year. I remember a similar comment in a similar discussion from the past and have wondered ever since if this isn't a difference between N & S deer. Agree it's not linear. I can point to bucks that didn't do much up until 4.5, 5.5, 6.5 and even a few 7.5s that suddenly blew up. Most that continued living were one year wonders, but a few weren't. Also have had bucks that have made 1 year drops and bounced back, others that dropped and didn't. I've had a bunch of bucks essentially flat line after hitting 3.5. I had a buddy that manages a natural genetics, 1800 acre high fence and his experiences are very similar in those regards.
All that said, somewhere over half follow a natural progression. Also, we have a lot of 3.5 yr old 8s that are 4.5 yr old 8s, 5.5 yr old 8s, 8s at 6.5 and so on....They put on a little mass and tine length, but they seem stuck at 8s and don't have it in them to break out of the 130s or140s.
I'm not saying one of us is "right" and the other "wrong," and I'm talking tendencies in all of this (plenty of exceptions). I suspect it's an issue of our environments impacting us in differing ways. It's a topic that I'd love to give you a call and get into in deeper detail on your experiences some time. If you're game, I'll PM you sometime in the future. I seem to have lost your number, one of the few skills I do have mastered (losing things)