Very interesting to hear your thoughts on this. You know, with the way they describe the universe its almost like they're describing a single drop of water which lay in an ocean of water. It seems incorrect to separate it from the whole. As far as the multiverse is concerned I think those universes would be separate entirely from the ones they describe that are too far out in the distance to observe.
It seems like the multiverse(s) would be something you'd have to punch a hole in space-time to access. Either that, or something separated by dimension as opposed to distance. TBH, I'm not 100% sure the multiverse exists, so all I can do is try and speculate on the matter. Welcome to steem! I found your post because I monitor the tag 'multiverse'. I look forward to reading more of your content.
I think they separate the universe due to their measurement of it through light years. As for multiverses who knows what a black hole or worm hole can lead to? Thanks for the welcome. I don't have any more content on space per say just one on God with the mention of a few space matters but i appreciate your input.