Perhaps you all already knew this, but I just figured it out, so just in case. I didn't want to do the DRL disable, and you can't access many of the nav settings while driving, but the day/night switch continues to be annoying.
While you can't make day/night a short-cut on the short-cut screen, you can put an actual choice button into the quick access menu that is already on the nav screen on the right hand side. How to do this is described on page 161 of the manual. Here's the link to the full manual (applies to MY '12, but perhaps there are similar options for other years) on the Pioneer site
http://www.pioneerelectronics.com/StaticFiles/Manuals/Car/AVIC-X930BT_OperationManual071211.pdf
But just quickly:
press "home"
press "settings"
press "map settings"
press "quick access selection"
From here there are 11 different functions (some are traffic, which requires the traffic module, plus Sirius traffic) you can select, one of which is the day/night switch. Once you select it, it will become part of the quick access menu. When you touch the menu, all of the functions are shown. You can add or delete the ones you want.