[talanum1 (OP)]

Yes. Otherwise objects would have been in more than one place at a time, and they would manifest as such.

Each one of us creates an absolute spatial reference point (halfway between the eyes), and Spacetime must know of this. So there must be continuous interaction of our consciousness with Spacetime.

[paul cotter]

Spacetime does not "know". It simply exists.

[talanum1 (OP)]

I beg to differ. Look: points of matter in space are viewed as such, but really they are four numbers indicating their position in Spacetime.

Simply existing is not what we observe: objects are at definite positions, and we can move them about. A calculation must happen for this to occur (Sigma F = ma). Simply existing as a computer does let this occur.

[Kryptid]

Relativity tells us that absolute reference frames don't exist. What looks like it's moving in one reference frame is sitting still in another. That doesn't mean that things would be in more than one place at a time, just that what one individual sees need not align with what another sees.

[Halc]

Each one of us creates an absolute spatial reference point (halfway between the eyes

This is a self contradiction.
If it is relative to somebody's eyes, it is a relative spatial point, not an absolute one. The latter would require no reference.
For example:

Look: points of matter in space are viewed as such, but really they are four numbers indicating their position in Spacetime.

So then what is the location of the sun in space? Your answer should include 3 or 4 numbers, units if you like, but nothing else. Those numbers should enable anyone in any distant galaxy to know where our sun is.

If you can't do that, then you've answered your own question.

[Eternal Student]

Hi.

   You've had some good answers already.    So I'm just to mention some slightly different things:

1.   You've used the phrase "spacetime" as in does spacetime have an absolute.....
    Spacetime is an abstract or mathematical structure and it doesn't need to have any absolute spatial reference point.
However, if you had changed the phrase to "the universe"  and asked  -  Does the Universe have an absolute spatial reference point -  then you'd almost be on to something.

2.   Does the Universe have an absolute spatial reference point?   Well, sorry, the answer is still proably no to this  BUT it might have a preferred or absolute reference frame.   That's almost half-way to having an absolute spatial reference point.    So, just to be clear, it would seem that you can still move the origin of that frame wherever you wish but you can't give it an arbitrary linear velocity or rotation.
      Specifically, there is only one frame of reference where the  CMBR   (Cosmic Microwave Background Radiation) is isotropic     (looks the same in every direction).

Reference:    CMB rest frame gets a fair discussion here:    https://physics.stackexchange.com/questions/25928/is-the-cmb-rest-frame-special-where-does-it-come-from

Counter-reference / special note:    Just to keep this all balanced.    See  Wikipedia article describing the Cosmic Microwave Background radiation,   especially the section about the power-spectrum analysis (similar to Fourier Analysis) of an-isotropies in the CMBR:   

  ..... The standard interpretation of this temperature variation is a simple velocity redshift and blueshift due to motion relative to the CMB, but alternative cosmological models can explain some fraction of the observed dipole temperature distribution in the CMB.....
    [extract from   https://en.wikipedia.org/wiki/Cosmic_microwave_background#Data_reduction_and_analysis   ]


Best Wishes.