It seems that switching is based on coral UI javascript events which doesn't make a call to page refresh.
All it does is changes layers from edit to preview and soon. I don't even see any configuration in console to have this feature enabled.
All these actions happen in the js files under the following folder
/libs/cq/gui/components/authoring/clientlibs/editor/js/layers
/libs/cq/gui/components/authoring/clientlibs/editor/js/edit