Hey GermanTux! You are mostly correct, although I don't believe you can do that through
Window Manager -> Keyboard as in there you can only set up Window Manager key combination bindings. But I assume you mean the shortcuts you can set up through the
Keyboard page.
I guess I could set up a keyboard shortcut directly from there, although I surmise it would do much the same thing that the line in the
~/.Xkbmap does. It is less than optimal for me, as it lights up the 'Scroll Lock' LED, rather than switching a flag icon on the taskbar or something (as the
xfce4-xkb-plugin did before). And another thing is that with the
~/.Xkbmap file method (given above) the keyboard layout switch is global, i.e. I cannot set it per window, per application, etc.
Nonetheless, if there is not other option, I am quite happy the way it is - meaning it does the job

And hopefully there are others who can find this useful.
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Will just await till the XFCE team add this, I guess!

I have grown somewhat comfortable with how things are at the moment and it is not much of an inconvenience, as job still gets done.
Happy Friday!!
