Firstly, in defense of Descartes. That quote is almost always presented without context.
Descartes was asking, “If perceptions and sensations can be false or mistaken, how do I know that anything exists at all?” In other words, he was applying extreme skepticism.
Then he concluded: “Even if everything I experience is false, the fact that I’m having any experience at all must mean that something exists.” In other words, even a false experience is something.
That’s all he was saying. It was not a statement of mind-body dualism.
But that wasn’t really your main point.
You’re talking about consciousness. And the domains or regions of consciousness.
I agree with you.
What people usually refer to as ‘conscious awareness’ is not really so conscious. The term is misleading.
Here’s a quote from my offline journal last week:
Everyday waking consciousness is a trance state characterized by the convincingly presumptive and misleadingly tangible perceptions of coherence and normalcy.
This is actually related to the question I asked you on the other thread where we were talking. To which you have not yet responded. 

So…