Personally I differentiate between 'awareness' and 'consciousness' and that makes it a bit clearer for me. Awareness of the 'suchness' of existence is what you're saying is the only thing we can be certain does actually exist. All the other "consciousness" things--self, self-awareness, thoughts, feelings, desires, even the senses themselves--are deconstructible into illusions.
Ehhh subtle but I'd say it's the suchness itself is what is guaranteed to exist. Awareness of the suchness falls into your latter category of "just a mental object."
> Consciousness is the only thing we can be absolutely certain does actually exist.
Unless the "consciousness" that you're talking about is the same as the suchness? Is the distinction that the suchness is somehow conscious/aware but not "conscious of itself"?
Okay, I think that's basically the distinction I was making between 'awareness' vs 'consciousness'. I guess it's not workable, since 'awareness' does not seem to communicate that concept well even to someone who knows the distinction.