Aww and there I was thinking it was perfect What problems does it produce?
Well, have you tried pressing "Shift", "Enter", "Ctrl", the arrow keys, any of the numpad keys...? Either nothing happens, or totally incorrect characters appear. There are also differences between browsers, in Firefox, pressing "Shift" produces a graphical element but on Edge and Chrome nothing happens.
I haven't checked it thoroughly, but the default "Keyboard" Plugin seems to be a lot more predictable and functional. It just doesn't register "Spacebar" as a string. But this can be easily implemented with an extra event.