Hmm, are you sure about that?—I could swear I saw a couple of videos where crossfades were being created/adjusted in what appeared to be a main track view, but maybe I'm just not familiar enough with Cubase's UI (or maybe it's a limitation of the particular version of Cubase you're using?).. In many DAWs Fades created in an audio edit window would be destructive (rendered), while fades in the regular track window would be non-destructive (on the fly, more flexible but more CPU-intensive), but, again, I don't have Cubase here to check it out (the DAWs I use (Logic, Pro Tools, etc) do crossfades in their main track areas, via handles or the equivalent)..
At any rate, if you got it working then I guess you're good to go.. :-)