I have an EliteBook 735 G6 and I tried the keyboard setting from: HP_EliteBook_745_G5#Function_Keys
Sadly my "call key" seems to send three key codes: CTRL, ALT_L and 66
So the remapping makes it send: CTRL+ALT+INSERT
Do you experience similar problems? Feel free to send me an email: kolAflash@kolahilft.de
I rarely use the keyboard these days because I'm working at home with an external keyboard.
But, when I used (today for example), I didn't have problems.
In my case, my call key only gives 66, and the hacks works.
It is true that I notice some times when it doesn't work, but I never check the reason because it usually works.
However, it is quite crazy that the call key send 3 keys at the same time...
three keys at the same time are definitely crazy!
Nevertheless, I might found a way to deal with that: https://github.com/philipl/evdevremapkeys/issues/4#issuecomment-639738690