Originally Posted by
Jane-DoH
....using the vortices generated off the tips of the canard to amplify the vortices off the delta-wing.
My guess is, that there you're confusing 'wing tip vortices' (from the canard in this case) with the 'vortex sheet' behind the canard,
Which acts (as suggested) not totally unlike a 'chine', while having advantages as a control surface at the same time.
As to your "when?" question, I have no idea, and I'll leave that to the historians here on PPRuNe....