Yes, they may use synthetic AMS oil for the engine shoot out in the magazine competition, but I can almost guarantee the engines used in the competition were not broken in using synthetic oil. I'll also bet most - if not all - of those "shoot out" engines used roller cams rather than flat tappet cams.
You need to break in flat tappet cams using oil with sufficient amounts of zinc in order to keep the lobes from going "flat". IMO, You should also continue using either oil with zinc or use zinc additives with flat tappet cams.
