The inflationary epoch where it expanded by 10^78 in volume happened in the first 10^-32 seconds. The furthest galaxy we can see (fairly poorly) is 300M years after the Big Bang. It's likely if time or the rules were different, 300M years was enough for things to mostly die down to steady state. And as you say, they match more or less but those errors could easily hide remnants of when things were different. Of course, these are all numbers that assume the Big Bang theory is correct which is difficult to impossible to falsify since we can't possibly observe or test anything from that long ago. We'll have to wait to see if refinements to our model that clear up contradictions change what we think about the beginning of the universe and other boundary conditions.