I think the question may boil down to resistance. With smaller diameter there would be less resistance and you could reel faster. There is also the stretch factor with mono that may mean you'd have to reel in a little more if the line was stretched on that cast because of a hook set or snag or whatever.
The reel has a ratio that will retrieve the same amount of line per full rotation. Because the braids don't stretch as much it should be more consistent.
I'm not sure why any of this matters. The differences I would think would be minute.
Where are the scientists?