The use of VIFFing, like the Cobra manoever or John Boyd's Flat Plate will have no influence unless it is practised. Overshoot tactics require timing that only comes with practise. Every tactic has a counter tactic. Can VIFFing counter a rolling scissors? Try it.
The use of ACM is not relevant to primary strike aircraft, but it's what fighters do. Regarding the relevance of the Cobra Manoever, although it is said to be worthless by Western military tacticians, the list of western aircraft now said to be Cobra-capable is growing to include Raptor, Gripen, Typhoon, and Rafale. Lots of new battle-iron performing useless manoevers. Maybe it can even break radar lock by minimizing doppler signature, like the Russians claim.