Let me share a real eye opener with all of you...
I own a .375H&H mag and let me tell you, that gun bucks like a mad mule! People say that it has more of a push than a kick - well, I can kinda understand that, but don't be fooled - it KICKS! Thing is this, I mounted a 1.5x-4.5x scope on it. Guess which one - an Elite 3200 with Firefly. Stated eye relief is a constant 3.6" and I thought that it wouldn't be enough. Well, as it turns out, the scope has not only held up perfectly, but eye relief was fine - never had a problem. Keep in mind that we are only talking about a $160 scope here, not a $400 or so Elite 4200, etc.
I also own many other heavy kickers and, for comparison, I own a 7mm Ultra mag, and it strikes like a Cobra - VERY SHARP AND FAST RECOIL! It wears and Elite 4200 4x-16x-50mm AO. I think eye relief is 3.5" and, believe it or not, eye relief is also fine as I have never had a problem.
We all tend to think that we need a foot of eye relief (I used to), and of course the more the better, but if I can use 3.6" of eye relief on a .375H&H, and 3.5" on a 7mm Ultra Mag, then it should be fine for all of you too. Keep in mind, however, that shooting position and stock fit is just as important as eye relief.
Zachary