I have used this tool before this announcement (I even wrote a post about using it) and to be honest, it is a really useful one. At least, my main use case is with my non-tech-savvy clients (I work as a freelancer).
Usually they don't know really well how to explain the changes they want to the UI but when I installed this tool in our project, they just used the preview environment to modify it with a visual editor and I got the suggested changes as a pull request automatically.
So, for me, it has been really useful. Kudos for the team!