As other threads have discussed before, we already know that NA and FI cars can't use the same correction factor. I detailed it in another one of my posts, the correction factor would depend on how much boost you're running. So unless the dyno operator asks you how much boost you're running, I can't see the correction factor that's applied being accurate.
Myself, I believe that there shouldn't be any correction factor applied at all, since it's just false numbers and not the real output. A car at higher altitudes puts out less power, and the dyno should reflect that. Trying to compensate for it really only makes the person feel better.
