On Honor MagicBook (basically Huawei MateBook) I have got Fn key to work as a trigger, that is it works the way, say, CapsLock works - hitting the key turns key’s led and FnX keys, and the next key hitting tuns the led off as well as FnX keys now work for backlight, volume and so on.
I’d want FnX keys to be turned on only during holding Fn-key (the way modifiers as Shift or Alt do work).
Ok, let it be this way
Initial guess was I am just not aware of some configuration way (say, other input devices like mouse and touchpad we can fine tune with xinput).