Here is what my friend had said about this subject.
MBHD
"Feel free to post the below response.
....
Altitude compensation is not needed with a MAP based system. MAF based systems benefit from altitude compensation. If one needs to adjust the tune, while driving, changing altitude or not, then the tune needs to be improved. This holds true for any EFI system.
....
Ray"
If you just copy and pasted, it says right there.
