All this hypothesizing about how dark matter behaves seems awfully speculative, since we believe that it doesn't interact with normal matter except by gravitational attraction.
So, is it the same temperature as the normal matter? If assumed so, why? How would energy transfer between it and normal matter?
Does it have "black matter pressure" by interacting with itself, or can it collapse by gravity without any regard to temperature of itself, not to mention the matter around it? Whatever you think, why do you think that?
It seems some theorists are eager to
postulate things that make their theories seem plausible, while not pursuing the related concepts that could derail their theories.
We are to the point of
inferring about 95% of the matter/energy in the universe is things that we do not understand and that do not follow the rules of the 5% that we do understand. Yet, we keep applying those rules to the other 95% whenever we don't have
proof that they don't apply.
Not logical.
Once we get past the CBR to earlier times, I doubt we have any idea what forces were dominating. The quantum mechanics theorists take over because we are extrapolating expansion backward towards a point, and they are the ones who think they understand things when they are smaller than what we normally experience.
But, even in the temporal interface between astronomy and quantum cosmology, do we really understand what was happening? Why could dark matter
not have started making mass clumps of regular matter far earlier? And, how do we know that there were not small black holes created by the Big Bang that have become the seeds for the galaxies we see today? Some are studying that, but with what physical rules for dark matter? See
https://www.sciencedaily.com/releases/2022/08/220810210334.htm .