Doesn't look like it's changing the way the game looks through the oculus.
I set the Right to 2500, saved Oculus looked normal. Really wide on the desktop window.
set the Right to 500, saved, Oculus looked normal. Really skinny on the desktop window
So looks like it changes the desktop window.
If in doubt back up your original before you start playing around.
The main reason we did this was so that recording the desktop for filming fights with the views incorporated in the video.
So far haven't been able to get the GeForce to record what I'm seeing through the oculus and haven't been able to get ah film viewer to show the views used when fighting in the oculus. So it's really just a hacky way of trying to get some filming to look somewhat normal, although it's only showing the right eye view on the desktop window, which is odd anyway.