If this is in fact the case, then I would agree with others that have stated during previous threads that spin & non-spin boats should not race, or perhaps even be on the same course together. In fact, any boats that have grossly varying downwind sailing characteristics should probably not be on the same course. Clearly, this interpretation of Rule 16.1 would give the windward boat a serious advantage when passing a leeward boat - the leeward boat has no defense.