Probably none of these, will add a few later…

One missing feature: That which either disambiguates or reambiguates the localized experiences natural to organisms, and, particularly, organisms capable of asking questions in a representational context.

I suspect that, first, we would have to carefully define consciousness. Because consciousness has occult (hidden) layers and features. And appears to »require what we would usually call unconsciousness (sleep/dreaming).

So I think this question has to be framed with adept care and awareness.

That said, I suspect it might be a layered array of extremely exotic feedback activities organized both locally and nonlocally, profoundly influenced by context and culture(s), and probably either linked to or participating directly (possibly emerging from) contact with advanced (and primordial) nonhuman intelligences.