Does it lower wear on the notebook's build in display if you use an external vga or dvi display? What setting about the display should you select in order to lower wear on the notebook's build in display? Can you turn off the notebook's build in display? Gnulinux system.
This was something you had to be moderately concerned about on laptops which used CCFL backlights (circa 1990s to mid-2000s). CCFLs would gradually fade in brightness with use, and burn out in 4-7 years of typical use. Leaving the screen on all the time or using it a lot would cause them to fade or burn out sooner. Repairing it usually cost anywhere from $30 to $150 in new parts (and extra for labor).
With the advent of LED backlights, it's pretty much a non-issue. Unless you're leaving the screen on 24/7, the LEDs should last several decades.