To De-Smog or not to De-Smog...

No, still incorrect. There is no such thing as an "EGR compatible" slant-6 exhaust manifold. The differences in various slant-6 exhaust manifolds have absolutely nothing to do with presence/absence of EGR. There is no such thing as a slant-6 exhaust manifold with provisions to interface with an EGR valve; there are intake manifolds with/without this provision.

E.G.R. stands for exhaust gas recirculation valve it is used to reduce the formation of NOx by introducing a small amount of exhaust into the combustion chamber it is connected to both the intake and exhaust