The mainstream size estimates haven’t grown for many years. These aren’t based upon how far the best telescope can see, but upon other things.
This is true. You are speaking of a mathematical estimate based on a ton of presumptions about the 'beginning' of the Universe, and the 'weight' (amount of mass).
It is also well-known that this 'model' doesn't fit the facts (kinda like the GW issue), and scientists had to make up a fudge factor called dark-matter.
Still, it is a 'guess', and I was talking about the 'observed' (whether visually or via other parts of the EM spectrum).
So, mainstream size 'estimates' may be correct, or may not. We have no proof yet.
If and when we are able to 'observe' the 'extent' of the Universe, what will we see just beyond that?