It is possible to export parts to standalone, but it involves some amount of coding. But again, if you are already using the Unity version, I'd think there is no reason to use the standalone version at all.
I might add a brief guide to the manual, regarding adding or editing animations. Since there has been a lot of people that asked about it.
As for our focus right now, we are currently in the middle of experimenting with something, that I'd think will benefit the tools and open up new possibilities for the tools in the future. The separated parts will most likely come along with that, so it might be a while. And to clarify again, it won't be for each part, but as a separated character as I shown in the preview image on my previous post.