'The downside is that we keep our characters in a certain timeline, and we cross over into other places.  Having some duplicate over in that world doesn't help with that or push us forward in terms of story.'

[@Enki]

Well, there's no particular reason why the Arena multiverse can't be part of your character's timeline, no matter how expansive the universes of the Arena are they don't span into other sites, so your characters have essentially punched a hole into another dimension of dimensions to look around. Which is really hard to think about.