You don't need to get the MAF reading right before removing the sleeve, the sleeve is there to get the MAF reading right so your stock tune will accept the intake as correct. With a tune you can remove the sleeve, increasing air flow to the design limits of the new intake.
Think of it as buying a shoe that's too big for your foot, but which comes with very thick socks that allow your foot to fit. Get a tune, like ingesting human growth hormones to make you a couple inches taller and suddenly your foot fits the shoe without the special thick sock.
Yep, Trifecta, the Roids of the Sonic. But in a good way!