"If we have 10x the mass of matter, that would mean the gravity would (given current theory) certainly cause universal deceleration and gravitational collapse producing the inevitable big crunchie."
No, it doesn't mean that at all.
Think about it, this changes nothing, for the 'reality' is what we see & observe.
In this case, as Hubble himself observed, the universe expansion is ACCELERATING.
I would bet, on my own logic, that there are theoretical physicist out there that do not have a clue
what they are talking about.
I have the 'logic' to know what the conditions were in the early moments of the universe, one of those
conditions is that the expansion that began back then has never stopped, for one simple reason.
There was nothing external to the material to make it slow down, which is why it kept expanding & there is\was no 'vacuum' effect pulling back on it despite the knowledge that there were Black Holes early, these being formed in other ways beside the collapse of early massive stars.
The expansion was not uniform, it could not be, because the formation of Baryonic matter is testament to that fact, though it does give provision to early development of Black Holes, at least that is my thinking.