Hi, gdad-s-river!
Technically speaking, yes we can do it!
With DraftJS, one can render custom blocks in the editor with fancy backgrounds upon which the app's users should be able to write "fancy font" text in realtime.
We can use one of the many existing solutions to convert the generated HTML from the editor, to a canvas; and from there to a required image format!
But sadly, I don't know of any existing solutions which achieve this! But it is not hard to do a DIY! Let me get you started👇
Hope this helps! Do hit me up if you run into any blocks! :)