Here are the files /var/log/Xorg.0.log (=/mnt/wkg/.session/var/log/Xorg.0.log) after 2 boots from fresh installs of easy 6.0, one with language=de and another language=fr (Remove the false gz extension)
The real differences start with "config/udev"
In fr
[ 40.568] (II) config/udev: Adding input device Logitech USB Laser Mouse (/dev/input/event1)
[ 40.568] (**) Logitech USB Laser Mouse: Applying InputClass "libinput pointer catchall"
[ 40.568] (**) Logitech USB Laser Mouse: Applying InputClass "evdev pointer catchall"
etc
In de
[ 43.619] (II) config/udev: Adding input device Power Button (/dev/input/event3)
[ 43.619] (**) Power Button: Applying InputClass "libinput keyboard catchall"
[ 43.619] (**) Power Button: Applying InputClass "evdev keyboard catchall"
etc
Still so mysterious