Yes, and i got it running somehow now, but it is a hell of a blueprint.
if u are interested in my solution, here it is, but it was hard to make a screen of it 
The lightgreen and brown parts is, where i deactivate the other camera or activate it to switch back with my CurrentViewTarget.
I am sure, i can leave the cast part away without any problems, but this way I am sure, the camera and the springarm are de/-activated as needed.
Not sure, if that might affect the performance, if i deactivate a camera which I don’t need at the moment.
