A bit of history here for those who care about such things. Our games have always been 320x200, from back in the freeware remake days to Order of the Thorne and Roehm to Ruin. When we started on QFI we very nearly went with a LucasArts style "always on the screen" interface which was why we added 40 more pixels to the height, that way we didn't have to make 320x160 graphics which is very limited. (The combat GUI is a remnant of that LA concept). When we went with the more traditional Sierra pulldown menu we'd already done a large portion of the town and Volksville Woods backgrounds at 240 height so ... we left it. It's actually been hurt us commercially to have it at the weird square resolution it is, I'm not talking millions of sales but we have had consistent feedback that the letterboxing on some monitors was a game breaking issue for some people.
So the side borders is actually what we're trying to do away with, currently the game displays in side borders on tablets which is something we're trying to port to in the near future. Coming back to a more standard 16:9 ratio fixes that as it upsizes properly. The system Steve described above decides where the screen begins it's display. 0,0 or 40,0 or somewhere inbetween, and the game will scroll up and / or down depending on whether we've locked it or not.
~ Shawn
BTW, I think you're drawing a pretty long line to connect changing a change in aspect ratio to censorship!
EDIT: It can't be made optional, to answer that question directly. It's a setting within the game engine that can't be changed at runtime.