Well, Battle for the Abyss takes place almost entirely while in Warp transit and spends a lot of time over how screwed up it can be. Unfortunately, the story doesn't contribute to advancing the HH, but does demonstrate that not all the marines from the Traitor Legions were traitors.
The White Zone is for loading and unloading only. If you have to load, or if you have to unload, go to the White Zone. You'll love it... it's a way of life.
: Cigarettes in space?
: It's the final frontier, Nick.
: But wouldn't they blow up in an all oxygen environment?
: Probably. But it's an easy fix. One line of dialogue. 'Thank God we invented the... you know, whatever device.'