Short version: Can you create an instance of a symbol using Javascript?
Concrete example: Imagine you want to make a specific object sparkle by creating a symbol that takes a sparkle image from 0 alpha to full and then 0 again, and spawning several instances of that symbol randomly across the object. Sure, you could just manually create 1000 instances of that symbol, but I would much prefer if I could place some randomly with Javascript.
In the above example, you could use a symbol, create the sparkle, and put them where you want. Then you would only need to create one symbol, and then you could use script to randomly pick which one to sparkle ?