I could have sworn I mentioned this in a previous annotation, but I couldn't find it, so:

My original conception of hyperspace in this universe is that you shouldn't be able to see stars while in hyperspace. But that'd look dull as a background and somewhere along the way when they first went into hyperspace I simply pasted a starfield background in as usual - and I've continued to do so ever since.

So now my conception of this particular instance of hyperspace is that it's an alternate dimension through which the starship travels and in which travel distances don't match the corresponding distances in realspace, but apart from that property it's actually just a normal space, full of matter and energy, and stars and planets and stuff. So there are potentially beings who evolved in hyperspace and for whom the normal universe of Spanners, Serron, et al. is a "hyperspace".