VO2 max is just a weird metric to use. Some of the bes tin literature didn't do very well, it's pointless to compare it to presumably athletes off a huge program cause we wanna compare it to the program of 5 years ago, and gas exchange machines have completely lol variability when I did a bit of research on it a few years ago
We don't have to operate on actual VO2 max values. I gave examples of relative changes. My point is that there's two-fold optimization possible and I'm just speculating regarding those two ways (increase of max. engine power vs. increase of efficiency for longer duration).