However, Eberron is not necessarily only one world. It could be one world or a whole universe. My concept gives you that freedom. That is what I like about it.I've come up with a somewhat interesting idea...
Eberron's hidden status in the Great Wheel is able to work largely because it is one world; one world out of many within the Material Plane should not be too difficult to hide, and escape the notice of several preoccupied deities.
My suggestion is that they are to far out that they are not known. The BE is so hostile, even to gods, that most, if not all, gods don't know anything about the Aether Realities. Spending that much time in the BE, to get to the Aether realities (and it would basically be a shot in the dark) is extremely dangerous for a being as luminous as a god. It attracts Eldritch titans look moths to a flame.But the Planes of Magic, or what @dave2008 calls the Aether Realities, are many. There are something like 80 known planes. And lore says that although the number of planes is probably finite, there are so many it is impossible to count them all.
With such a high number of worlds, hiding all of these in one area would simply be impossible, and the "null space" of impenetrable area would be common knowledge, even if not understood, by the gods of the wheel.
I agree with that, I just place the everywhere in the BE. I tried to insinuate that in my sketch with some shaded "realities" hidden the darkness of the Blind Eternities. Those are undiscovered realities.So how does one hide countless worlds? By placing them everywhere.
I generally like the concept, but to me it is more complex than it needs to be. I also don't like placing all of these in the prime as the prime has certain rules. By making them different realities, each reality can have its own rules.Right now, Spelljammer lore has each D&D world in the Material Plane within its own Crsytal Sphere, that can be reached via Spelljammer. My suggestion is that each plane is also within its own Crystal Sphere; the difference, is that the Blind Eternities cloaks them all, spread out across the Material Plane like a web.
So there are the "known" worlds, easily accessed by Spelljammers and connected by Phlogiston routes. Then there the the "cloaked" worlds, or Aether realities, that are also spread out, but cloaked in the Blind Eternities. The cloaked worlds connect to each other through tendrils of the Blind Eternities, a web that connects the planes like nodes, a web that Planeswalkers access to travel between worlds. Planeswalkers also can't access worlds beyond the web.
My point is the BE is all null space, even to the gods. Anything beyond the border realities is essentially unknown, and event the border reality is heavily shrouded by the blind eternities.This way, there is no big "null space" that the gods will easily see. Instead, there are much smaller cloaked worlds all across the Material Plane, each one going unnoticed.
I like your ideas, they just don't accomplish for me, what I want from a unifying cosmological frame work. Not that there has to be one, I just enjoy thinking about it.