I have a RPi 3 running LibreELEC (official): 9.2.3 (RPi2.arm). It is using the Smarti Pi Touch 2 chassis and the RPi touchscreen and the Estouchy skin. I noticed that when I go to Settings -> Libreelec config there is no back button. You're stuck unless you have a keyboard attached or do a power cycle.
Fortunately I have a spare keyboard for the very few times I go there.