Plugin works great, it looks amazing, but kind of breaks the WordPress consistency. It introduces third new way (1. admin, 2. customizer, 3. front-end) of editing content and I don't like the confusion. It should move to Customizer.
This is a no-brainer and there is no real argument against the move. It will probably move the development back a week or more, but better now than in future, when it hits the core. Editor will probably not look as slick as it does now in admin bar, but this could be added to customizer somehow.