Thats interesting that you see it that way. I see it the other way around.
We have another option if you want to jump on the Cobb AP boat. The Racetuner Pro software allows for speed density tunes but I have to check and see if it goes for Legacy GT as well...Sent an email today to find out.
I have the scaling for the AEM 3.5 bar MAP sensor, thats what I use in case I feel like running 50PSI...lol