Can I then assume that if your bow is finely tuned that the F.O.C. is not as critical unless there is a stiff cross breeze?
I think it depends on the bow. Some need all the help they can get. It seems to me that poor nock travel may affect broadhead flight more than it does a field tip. For instance, if I shot an arrow out of my bow, with no tip, (unlike my friend' s bow) it would probably hit the target sideways, no matter how I tuned my bow. It doesn' t seem as forgiving in this area. However, when I get my FOC up to about 11%, fixed blade broadheads fly quite well.