Thanks for the update. I think using Save means that the app will be based on non-optimal set of HTML/CSS/JS files. On the other hand, the Publish feature longer works in GWD, as it now forbids any non-existing paths (which is the case when you set the src attribute of the iframe to non-existing application html file).
As such, we no longer recommend using Google Web Designer in Verge3D pipeline and removed the GWD part from the documentation. 3D designers are encouraged to try more production-ready tools such as Webflow.
