I've seen lots of answers here about the episode "Force of Nature". The episode is about scientists discovering that travelling at speeds greater than warp 5 destroys subspace. It's been stated a few times here on this website that voyager's nacelles are made in a way that negates this effect, and that the rotation of the nacelles has something to do with it. Is this actually canon, and if so, how does rotating the nacelles upwards fix the problem? The Enterprises all had nacelles that were angled up from the hull.
According to the unpublished VOY Season 1 edition of the Star Trek: Voyager Technical Guide, by Rick Sternbach and Michael Okuda, it was suggested that because of the variable geometry pylons, warp fields may no longer have a negative impact on habitable worlds as established in this episode.
The idea was that as the Voyager went into warp and the warp bubble was forming, the warp engines were shifted; and this single shift (at the formation of the warp bubble) altered the nature of the warp field so it would no longer damage subspace.
So it wasn't the final position of the nacelles that prevented damage to subspace as it was the movement during the formation of the warp field, which changed the nature of the bubble surrounding the ship.