We can ‘point’ beyond the observable universe, in the sense I mean. We can meaningfully (if theoretically) talk about space beyond our sight, and distant past and future times, in ways that we cannot for other universes. We know that the physics of our universe, beyond the observable edge, has to mesh with observed physics. There are no comparable statements about the physics of other universes, or the nature of the relationships between them.
If it is curved like a sphere then it is 3D space on the surface of a hypersphere. Expansion would be like drawing galaxies on a balloon’s surface and inflating it. That way there is no edge. It would be weird if space didn’t loop back on itself then there would be an edge of the universe.
Edit: unless the universe was completely infinite - then I guess there would be no edge. But I’m not sure how a singularity could lead to infinite space.
The universe, as we know it, is an elaborate thing that seems to be comprised of many layers, some that we have yet to discover, comprehend, or even imagine. The layers seem to go on and on and on, like some sort of infinite onion.
When European explorers arrived at the southern end of Lake Michigan, they asked the natives what this place was called. The natives gave them a word in their native language that translates to something like “reeks of too many onions”. The name, of course, stuck.
Therefore, I submit, this universe, all its companions, and the ultra-æther in which they reside deserves to be known as “Chicago”.
It might help to think of the singularity as being infinite density, rather than thinking of it as being zero size.
Then there’s the fine tuning problem. I think it is more reasonable to imagine a near infinite number of finite universes with different parameters than a near or fully infinite number of universes of infinite size.