How exactly do you imagine this feature working?
Currently to achieve a scrollable, typing dialog effect with multiple fonts or webfonts, I am using Rex's Typing, Scrolling, and TagText plugins and also Boundary for the scrollbar.
You can see my end result here:
It was not elegant or simple to setup, but I think you could look a these plugins/behaviors as inspiration for a better way to integrate features into the editor in a game-agnostic way.
Currently the scrolling is really cropping the lines of text in a buffer, instead of actually masking the text etc. It would be ideal to be able to mimic a true scrolling text field element as if in a browser perhaps.