Window does not accept focus option

Recently I started porting an app to Kivy for maintainability but I got stuck and traced it back to here.

I do not want the window to get focus, as it is an OSK.
In Qt this is provided trough an option (WindowDoesNotAcceptFocus), the target platform is X11.

Is this currently possible - if so - what am I missing?
Thank you in advance.

The change made implementing it in Qt:
Kivy does nothing more than reading from the event what comes to window focus.