Felix, Here is an interesting twist. I have reverted both grub and 00_header to the original (no 1920x1080 parameters) and executed update-grub2, and rebooted. The desktop comes in at 1920x1080. Currently, the only artifacts directing 1920x1080 are the xrandr scripts in: /home/user4/.config/autostart/eDP1_1920x1080.sh.desktop /home/user4/.screenlayout/eDP1_1920x1080.sh
It would seem the grub functionality triggered something that xrandr did not.