There is a problem I don't think anyone else has thought of, and I've brought it up before. That is, besides my opinion that the background constant equals '1' and is infinity. I will harp on it again.
Start with the (Planck) BC / BB. There is overwhelming light at every point. Encompassing every point(!), mind you. Does that light go out? No. Light continued, and continues, to encompass every point. There is no break in it in space and time. So, how is light just arriving here from 13.8 billion years ago, as light from a nakedly singular beginning of universe, when light has been here, at every point of the universe, continuously for 13.8 billion years (as the collapsed horizon of space and time infinity (having its own dimensional constancy of relative physicality that doesn't, and won't, ever show up as the infinity it is . . . even of time)?
In other words, all the light before light, that has been arriving at every point (that has been at every point, encompassing every point), going backward in time into infinities of time. Light said to be arriving here from a distance of 13.8 billion years (that cauldron of chaos would not permit it but say it does) would be 1-dimensionality drawing out of a multi-dimensionality. Exactly like light and all other physics here locally, it would be a future that in its own right already had a past (an infinity of pasts), as well as having a continuing future to the always dark universe 'average' point of t=0 (Now) (the 4th dimension of space . . . thus the point; the '0'-point).
The point is, though, there never has been a lack of incoming light to any point, already arrived at any point, including from the farthest reaches to the collapsed horizon of infinity. I mean, from a trillion years ago and more light was reaching from the collapsed infinity horizon constant (t='1') of 13.8 billion light years across the distance. It happens to be a constant of Planck Horizon.
Light before light. Gravity before gravity. Space-time before space-time. . . countless numbers of equivalent 4-dimensional spaces-times (sic), like equivalent masses-energies, in rank and file, so to speak, totaling a cauldron of universe 'chaos' ('uncertainty'). Just as with dark universes' t=0 (Now), the observable universe shows nothing of any true dimensions and dimensionality. It wouldn't of course, since with all distance going away from anywhere it seems to flatten out the look of the universe to a smoothly flat picture (a 'photo' constant universe: that photo constant being one of universe in endless beginning, the totaling up -- the merger / flattening -- to '1' of endless beginnings).
Thus, there would be no other side to a horizon constant of (Planck) Big Crunch (M) / Big Bang (E) equivalency. It's sort of like the Earth's horizons that have no other side to them since we are always in those horizons and, thus, can never reach them (they always remaining distantly constant to us) much less go beyond them. That horizon, too, would always open to a traveler since it is always opening in one dimensionality of it, always closing in another (Schrodinger's cat).