Asus N501VW with 19.04
I use an external monitor with the laptop lid down so if the kb light is on it gets too hot in there.
I don't see a Upower configuration file. Perhaps it is not installed.
In desperation I am running :
echo '0' > /sys/devices/platform/asus-nb-wmi/leds/asus::kbd_backlight/brightness
as a root cron every five minutes!
Cripey!