Yes, it is possible. I'll try to do it soon.

The default extension hotkeys can't be changed right now. One way to work around this for Windows users is to download and install the AutoHotkey program. Create a file named Firefox.ahk and then copy the code at the bottom and paste it into the file. Place this file in the Startup folder and then run it. Now, if a user presses Win-G in a Firefox window, it will invoke this extensions Alt-Z pause hotkey. The Win-G hotkey can be changed in the file to whatever hotkey is desired ( https://autohotkey.com/docs/Hotkeys.htm ).

$#g::
ifWinActive, ahk_exe firefox.exe
{
send !z ; Alt-Z extension pause hotkey
return
} else {
send #g ; Win-G hotkey
return
}