[quote=@Muttonhawk]
<Snipped quote by The WIP sphere rules in the doc>

Is there a reason why a more earthly sphere cannot take the above caveat and just pick whether it's more celestial or cthonic?
[/quote]

Nope. I don't really see this as an issue of classification so much as accessibility, though. Option C simply changes the classification around so that we can give some in-universe justifcation for easily accessible Spheres, like the dirt god living just under a hill where you could dig. Or the forest god's Sphere being forest.

This issue is really distilled down to the previously posed question of whether we'll tolerate gods essentially picking Galbar as their Sphere and dwelling down there, because the dirt and forest are effectively the same thing as Galbar. My leaning is no; I support option B and I find myself more inclined to agree with Octopus on most of what he's said about this.

For some it might be a challenge to think of some sort of Celestial or Chthonian Sphere (or some weird parallel realm, as you suggest) that makes sense for their character, but with a little bit of creativity I think it's possible to come up with something that's fitting, interesting, and not in conflict with the stated rules concerning Spheres.