Here is an air file editor:http://members.dsl-only.net/~eagle/
AirEd is the name and it reads the COF air file.
Problem is, no one is going to make basic aero adjustments in the air file. Because you cannot.
We are stuck with the basic GMax model. Generally, adjustments are made in the Cfg file each aircraft. The adjustments that matter for the 182S climb performance are induced and parasite drag given that engine/prop modeling is correct.
Has anyone sim tested to see if the C182S add in's perform better than the stock versions? If so provide some factual data.
I find a similar issue in 3US P47 where USAAF and Republic test data are available. The fighter doesn't come close to climb specs. Hence it's poor dogfight performance.