I read through the FAQ and did a search, and nowhere could I find this answered. If it has been, excuse my search-fu and enlighten me.
In the UA model, dark energy looms above and pulls everything towards it at 9.81 m/s^2. However, it obviously distinguishes between what to pull and what not to. Otherwise we would all be in freefall, as it would affect and pull us all equally as in this explanation that your own FAQ so sweetly links to,
you and the elevator could be in the gravitational field of a mass, for instance that of the earth, as long as the elevator was in free fall. In that case you, everything else within the elevator and the elevator itself would all be accelerated at exactly the same rate so that, inside, no influence of gravity could be detected.
As to what it pulls, that means we can rule out every single element known to humanity; there aren't any weightless elements that just float around! That also means the moon can't be affected by UA, as it apparently doesn't affect the elements that it's made of. The much speculated upon moon shrimp would also just fall right off the surface of the moon, even if we assume it somehow stays there through mechanics as of yet unknown; there's nothing holding them there!
To me this seems like UA simply does not work! Tell me how this mysteriously specific force works its wonders!
As always, I'll expect you to back up any new and/or undocumented statements and theories with at least some kind of factual, empirical and verifiable evidence.