The first paragraph isn't something relevant, that's just a bunch of commonly asked things about the universe.
Once again, the location of Exception isn't "At the edge of the Universe" it's "Outside the Universe". And not just outside the Observable Universe but outside the Space-Time Continuum. But as DTDT said, it doesn't matter if the Universe has an infinite amount of 3-D space because Space-Time Continuums are technically unquantifiable larger than even
High 3-A levels of space. The only true "edges" a space-time continuum really has if any are a beginning of time and an end of time. Empty spaces don't logically have edges.
The Secret Rings example is definite proof that it's just dimensional travel given he was initially warped to the "Space-Time Continuum condensed in a book". And that him finding a warp portal makes more sense than assuming he just ran to the edge of the Universe then through the spatial barrier, than went from the edge of the Universe to Earth. But here is not that much different. You don't have to fly through the edge of the Universe to fly through the dimensional barrier. It's the same thing as assuming someone needs to run a lap around the Earth to the East or West before they can rake a few steps north or south. We don't assume 4-D distance is beyond observable Universe.
And before you use the, "The difference is that the two timelines are being merged into one thus turning it into a quilted multiverse." You're the ones who brought up the Secret Rings example, where the very beginning was Sonic getting teleported to their Universe by the genie. But that's the exact same
beginning as Blaze's story where she was instantly teleported to Sonic's world.
"We see them physically move across space with no celestial bodies." That doesn't mean anything. We see them leaving a white spiral and approaching a purple spiral too. Seconds before that, we see the background look like that as they're transforming; they're standing on white panels with a black background. Are we going to assume the flew beyond the edge of the observable Universes in base forms? Or are we just going to assumed the Earth's sky and grounds just magically turned black? Anyway, different fictional works have they own methods of how 4-D space travel works; some show a vortex like background, while others can even make it look like standards space travel with a generic background.
Anyway, it doesn't matter whether or not DontTalk is knowledgeable on the verse. However, he is knowledgable on all the standards of the explained feats put together. He's knowledgeable on our flying from one Universe to the other feats regardless of whether or not the two universes are merged, he's knowledgeable on how a Universes/multiverses structure is generally assumed based on 2 or more of them merging together. And based on all of these analogies, the calculation is dependent on way to many standard assumptions being ignored.
But we can wait for him to comment again.