I think you are on the right track. In the overall game the inflation of the football really doesn’t make a great deal of difference if any at all. I suspect that the refs know this and are willing to expand the written rules to accommodate individual preferences by the QB’s.
As for the reasons why the footballs are not checked, my guess is that the same forces that persuaded the rules committee to allow teams to use their own footballs are at work.
I change the grips on my golf clubs every once in a while and while I have my preferences for size and feel, at the end of a round the score is pretty much the same.
Well, whether it makes a big difference or not, there could just be wink-wink nod say-no-more between teams. And the refs won’t get interested unless someone complains. If every quarterback has their own sometimes wildly different preference, it could just be every team is scared to ask the refs to check because they know the other team will ask in retaliation back at them. That happens in baseball when someone complains to an ump about loaded or scuffed balls, sometimes they know something is up but they probably have a pitcher on their team that does the same thing.
It would be interesting to know exactly how this came to the attention to the refs.
Freegards