Hmmmm …

I shall have to read more about it than have, but I’m sceptical.

It seems to me that this ‘System3’ of his is no more than a description of the ‘dialogue’ between the two systems that must, inevitably, arise as System 2 conflicts with System 1 — far from being a separate system, merely the process of their interaction.

Occam’s Razor applies: if you have to invent a third way to describe that which is adequately described by the first two … you’re wrong.