I was wondering if the UpFront designer is available as a plugin? I would love to be able to use it within a different theme (Divi). Otherwise it would take an entire site overhaul to convert Divi (which uses it's own builder) to UpFront.
If not, you should consider creating one (UpFront Page Designer Plugin) and selling it as a premium plugin. Elegant Themes has done the same thing. They de-coupled the designer from the Divi theme and it now can be used with any theme.