Ynot,
Is it not possible to say that when space-time did not yet exist there was emptiness? This emptiness (voidness) was always there and will always be there.
I look upon space as something subtle (a kind of rupa). I imagine space-time is like a very subtle field which expands and deflates in emptiness. I think space-time has a kind of very subtle structure, even when no visible formations have yet arisen.
Does the Buddha not say in DN1 that there are four grounds in which people can be called Finitists and Infinitists, and proclaim the finitude and infinitude of the world. There is no other way, he says. And all are wrong.
The case is described where someone claims that the world is infinite based on his own experience. This is a wrong view number 10 in the translation of Walshe:
2.18. [Wrong view 10] ‘And what is the second way? Here a certain ascetic or Brahmin has [23] attained to such a state of concentration that he dwells perceiving the world as infinite. He thinks: “This world is infinite and unbounded. Those ascetics and Brahmins who say it is finite and bounded are wrong. How so? Because I have attained to such a state of
concentration that I dwell perceiving the world as infinite.
Therefore I know that this world is infinite and unbounded.”
This is the second case.
And
§3.34. [Wrong views 9-12] ‘When those who are Finitists
& Infinitists proclaim the finitude and infinitude of the
world on four grounds, that is merely the feeling of those who
do not know and see, the worry and vacillation of those immersed in craving”.
Siebe