This idea has been merged into another idea. To comment or vote on this idea, please visit WEBFLOW-I-2051 Enable z-index editing via Interactions.
Currently there is no way to set preserve-3d without custom code.
When you create 3d elements that interact with each other changing Z axis and you want an effect like z-index switch on interaction you need to add preserve-3d to parent element in custom code.
Custom code works only in published site. So in preview mode your 3d effects looks a bit broken.
It's easy to recreate this by creating two elements one (A) on top of other (B). And then add an interaction that moves A behind B in z axis. (A and B parent element has to have preserve-3d setting for this to work).