I actually wasn't being sarcastic (Well maybe a little bit in my "PS" comment) ... I guess we'll eventually get on the same playing field ... I'm actually trying my best ... I'll practice more patience. You probably outrank me on that front .. so you can call me on it !
Obsessions ? Addictions ? yeah ...I have 'em too .. they come and go ..!! That's Ok.
I'm no expert on voids ... but I can't see why light (or radiation) can't propagate through one. And that wouldn't necessarily invalidate the definition of "void". I wouldn't think that light would be bent and hence, the geodesic path it would take through a void would be as straight as an arrow. (?). The void would still move away from other matter outside the void, I would think, courtesy of expansion, though.
These voids are interesting phenomena from a similar perspective as Black Holes ... except no mater, no gravity ... must be lots of theoretical stuff to look at there.
Cheers & Rgds