We kept our "L" corner as dead space. It was pretty much a no-brainer for us; having a "tray" cabinet (even a small one such as ours) for baking sheets, cooling racks, and pizza stones next to the range was non-negotiable. The only way to achieve that was to close off the corner space.
The dead-corner space came in handy though! When it came time to plot out where to locate the gas shut-off required by code (had to be within a certain number of inches or feet of the range), I was reluctant to shorten any drawers, or give up usable cabinet space (for the gas pipes and shut-off lever). I asked our plumber; if our cab installer cut an access panel in the side of the tray cabinet, could the emergency shut-off be located in that dead-space?
The panel is held in place with magnets, and a pull-ring was attached to the panel in case we need to pop it out to access the shut-off or the dead-space for any reason.
Q