I agree we are talking about a non-problem.
But as long as we are discussing :)
Actually, unless you're blowing teams out of the gym in every game, all your starters will play at least 30 minutes per game, often more.
My best player (a trainee) does (almost) never play as starter. He plays rotation twice a week and between garbage-time and foul-problems he gets more than 48 minutes.
Plus, what's the fun of having someone's third-string center topping all rankings because he played 1 minute and scored 1 basket on a tip-in, thereby getting himself the hefty per-48 average of 48 points and 24 rebounds.
Why do you rescale? In the stats, there should be a minimum number of minutes played. Among 500 minutes played (for examples) the stats in that 1 minute will count as much as those in any other minute. I don't really follow you here...
But you have a point saying that performance is not directly scalable.