VIFFing was never used during the Falklands: the Argie aircraft were at too far a range to get involved in air-to-air combat. If a Harrier appeared they ran: if they had stopped to fight they would have run out of fuel. The Falklands really were at the maximum endurance range of their aircraft
PS - VIFF = Vectoring In Forward Flight
And the US Marines invented it during a demo flight "just to see what happened if you tried it"