I know i'm asking a lot of improvments, but i really believe that you're plugin is a great thing that deserves to be improved to be the best of Octobercms plugins :)
What i'm searching right now, is a possibility to generate css responsive code for background image. It would be good that when you add a background image, it generates directly another css with the background with the css option image-set. And of course, it generates also the other image sizes in the media library.
I just integrate grapesjs into October CMS and not develop it.
In addition, this option is currently not supported by all browsers. Firefox for example.
background-image:-webkit-image-set(url("http://placekitten.com/344/300") 1x, url("http://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Banana-Single.jpg/688px-Banana-Single.jpg") 2x);}
<h1>CSS image-set (test for 2dppx)</h1>
<p>Do you see a cat or banana?</p>