I know, what you mean, but the way, FCp is handling it in a very different way, than fades applied in Audio Apps, like Ableton, ProTools and so on. The curvy line in between two keyframes in FCP does sound very different than a strictly linear line between two Keyframes in Ableton/ProTools. For me to handle this kind of Audio situations is very poor in FCP. I did a lot of test on this, cause I wasn’t sure at first if it’s my imagination, but the difference is quiet big.
Sascha