I’m going to answer your question from a completely different perspective than current physics.
I have been working on a New Way of looking at physics from Inner Space through Outer Space for the past 7 years.
Your question relates to Outer Space.
I believe the COSMOS is a closed system and cycles along a Cosmological Entropy Wave.
All Matter – Energy – aNd Dynamics: MEND was contained in a singular super huge Origin Particle 120 Billion light years in diameter before NATURE’S TRUE BIG BANG.
External Entropy 0, Dark Energy 0, Dark Matter 0, Pressure 0, Temperature 0.
Everything was contained inside HER Origin Particle.
After HER TRUE BIG BANG there were Universe Size Chunks, Galactic Sized Chunks, Solar Sized Chunks, Planet Sized Chunks, and Plasma and dust flying out into the newly formed Outer Space. Thus there is an Entropy level greater than 0. Dark Energy Spiking.
At the Core of this TRUE BIG BANG is a Super Vacuum Dark Hole. Literally a hole in space with a great vacuum energy.
As these Chunks fly out into Outer Space they have secondary, tertiary, and on and on various levels of little Big Bangs that increase the entropy and form universes, galaxies, stars, solar systems, planets, and more plasma and dust and increase the entropy. Dark Energy reaches a maximum and begins to decrease.
We even have tiny little Big Bangs going off in Outer Space today increasing the entropy.
And we have many more Dark Holes formed.
As the COSMOS is expanding from our view point which is increasing entropy it has already started collapsing at the CORE which is actually decreasing entropy. Thus one needs to consider total system entropy and not just conditions at individual points. The COSMOS after all is a very dynamic place.
When Dark Energy again reaches zero in the maximum expanse of the COSMOS, total system entropy maximum, the Vacuum Core Dark Hole will complete the collapse and recycle it all over again. And Again and Again. Thus the total system entropy will decrease in the collapse and thus a wave function develops.
A new singular super huge origin particle develops and external entropy is zero. Everything is internal to the Origin Particle once again.
Now to answer your question.
If you want to distinguish between the COSMIC beginning point of entropy, the peak point of entropy (prior to collapse), and the end point of entropy, you need to look at the rate of change of the entropy at each point. There would be a very high rate of entropy change in the beginning and a very low rate of entropy change just before the collapse, near zero change, and a very high rate of entropy change at the end.
Dark Energy can be a tracer for this, for Dark Energy at zero will mark the beginning of the collapse. It appears Dark Energy would increase again for a time during the collapse while entropy would be decreasing.
The catch is that the COSMIC Plane-Plain could be 120 Trillion light years in diameter and we can only see 20 billion light years of our local universe within the COSMIC Plane-Plain. I used Plane-Plain because the COSMOS appears to be a flying flat discuss shape, much like the Milky Way Galaxy.
Hope this helps.
You can see an introduction to my work and ask more questions at:
Sincerely & Respectfully,