ratiocinator
Lightly seared on the reality grill.
For goodness’s sake, drag yourself into a 20th century view of time.And all of those 32 hypotheses (if they really exist) ether: claim that the universe came from nothing or that it has always existed, (or are open for both possibilities)
My point is that for the there are only 2 possibilities
1 it has always existed
2 it came from nothing
(Space-)time is (according to our best relevant theory, general relativity) a four-dimensional manifold and a part of the universe. In that sense, it must have 'always' existed in the sense that it has existed at every point in time, even if the space-time terminates in past time-like directions through it. Looking for the reason for its existence at the earliest point in time (if there is one) is a bit like looking for the reason the earth exists at the North Pole.
If this view is correct (there are other hypotheses, but none are well tested theories, like general relativity), there is no 'coming from' involved. Things can only come from something else within time, which means the question of what the whole universe (space-time manifold) 'came from' is nonsensical.