Hmmm... Well I wasn't serious about the concept, not least because of Occam's Razor, but I thought that with it being a "scale factor", it could perhaps be understood from the reverse perspective.
Having given it more thought and a bit of reading I'm of the impression that everything...
Here's an oddball thought... What if the universe isn't expanding, but instead everything is contracting and being correspondingly scaled down. The space between objects in the universe would appear to be expanding while everything in the universe shrinks by the same amount. The speed of light...
I've been wondering about this recently.
Assuming that the Hubble constant is constant through time as well as space then the observable universe should be of a constant radius. This radius would be the distance that is expanding at the speed of light.
Note that I am assuming Euclidean...