It's useful if you're writing JS code inside a web page, and want to use the features of the outliner to automatically generate curly braces and semicolons (CBASs) in your code, the same way Frontier does it for UserTalk code.
All text nested underneath it would have curly braces and semicolons automatically inserted in the right places.
The CBASs are generated as the object is served, so no compilation is needed.
It will generate the curly braces and semicolons even if they're already there, so you can't really use it on existing code without converting it.
I think it's pretty exciting!