I don't always agree with IO's delivery, but he knows exactly what he's talking about here.
The throat required for a 75 A-Max vs a shorter bullet? Here's a thousand words with the 75 A-Max and the 50 V-Max seated to touch in my rifle. The mag box may require massaging to run a 75, but not the throat.
As far as long range trajectory, go back and read what IO said again.
In my 1-8 twist 223AI, I get 3050 with the 75 A-Max and 3600+ with the 50 V-Max. Want an education? Run those numbers in your trajectory program and see which one shoots flatter.
And frangibility of the 75 A-Max? You have to see it to believe it, it will seriously mess stuff up.