By using the term "consensus" aren't you admitting this material-universe-dream is external to you, and therefore indistinguishable from the concept of an "external world"?
It depends which "you" is being referred to. The human you are talking to right now is part
OF the "external world" you see?
We are part OF the dream.
Envision for a moment that this is all a dream in God's mind. We the characters localized inside this thing called the universe, are dreamed things. Indeed our bodies are made OF the universe, of matter. We arise from it. We do not come "into" it.
It is about finding what exists objectively at the absolute level, which is above and beyond what is objectively true in this dream.
So absolute I am meaning, that even if there were a creator God, or this was a simulation on a computer, it would be the origin of THAT too. We are going right to the source. And I am saying that at the source, there is no such thing as other. It is total nonduality.
When nonduality is experienced by a human, which is our finite selves, the experience is equivalent to nothing. When we go under general anaesthesia, the nothing in between is total absolute nonduality. Because the monent you experience ANYTHING, you are creating experienceD and experienceR. There is no experiencer without experienced. There is just nothing. And that is fundamental absolute reality.
From our finite selves, there is an illusion of the external world like a dream, but there is nothing actually out there beyond mind. I wrote a piece on Reddit proving this mathematically. But logically it can be shown too, since an object is nothing but what it is perceived to be. It is possible to experience various models of this "external world" and all function as expected like the example of the stretching or shrinking TV screen and tape measure. When multiple models of the world work, there is no way to be able to determine which is right or wrong.
A space alien might perceive the color red as blue. But if both taught "this is what red looks like" when seeing that specific wavelength of light, we would agree "hey look there's red". In that very simplified version of the issue, we see that there is no way to say whether upon exiting the mind the thing is actually red or blue.
Consider for a moment if you were tasked to draw the room around you as it IS rather than as it appears, how would you begin? Color is immediately out. We might instead choose to draw some squiggles to represent a wave of light (color). But a wave is still form, you are still drawing a shape which requires seeing and perception.
It gets more interesting and obvious with spatial dimensions, though, because that is where we can most easily see our measuring tools are meaningless to tell us what is really there, because they too are subject to perception. And thus a person could see something as being much different in size while the measuring tool being a material object alters size to reflect the perception, while the numerical figure remains the same. And then we can ask "what exactly IS a 30cm, when removed from perception". Am I making sense?