Lanefan
Victoria Rules
I don't like the concept of "multiverse" in any form, nor "parllel universes".I hate current D&D's peculiar use of multiverse. In most media it's a convention that allows you to have different versions of the same thing. Here it's an excuse to impose a single monomyth on all settings.
There is and can be only one universe, which is why it's called a UNIverse: 'uni' means one. All the planes etc. that might from the inside all look like their own universe are merely sub-sets of the one actual universe that contains them all.
So when you look at the diagram of the great wheel, the whole diagram represents the universe.