This is an i-zombie at the behavioral level, so it isn't entirely unrelated. You're right about the complete-physical-description level, which is the philosophers' favorite. The authors do point out that the poorly anesthetized are not i-zombies at the functional level, which also implies that they're not, at the complete physical description level.

What puzzles me is why they appear to favor functionalism for (e.g.) pain, over type-identity theory. None of their main points depend on it. And the supposed "advantage" of functionalism, that it affirms the mental as the source of behavior causation, applies equally to type-identity.