Hello,
I am sorry about the issue you have with zooming-in-out animation.
GWD is looking to enhance the way animations render on browsers, so please stay tuned for upcoming releases.
To workaround the issue when using Z axis, you might want to try to add negativeZ px value to the background elements, so the image animation stays on top.
Could you try it and see if that works?
Thanks,
Mariko (GWD team)