There have been some guys who did put spinnys on their A cats, not sure if they put a stiffer/stronger mast on first, I doubt it, and their spinnys were probably smaller than the 17sq.mtr on the F16.

Dont't forget the A cats hulls, in addition to being lighter, are two feet longer, (that's 12.5% longer) and I think that makes a speed difference as well as the taller/larger main, going upwind.