Brush collections with use of instances instead of duplicates

I'd love to be able to create brush folders that contain instances of my existing brushes, to avoid creating duplicates in order to have them in two or more different folders.

It would help to manage different workflows for varying projects, especially when there are already a lot of brushes loaded up. As an illustrator myself that use many many brushes that would make organizing brushes and workflows much easier. 

Maybe these folders could work with just a simple tag. Like smart folders. You could just add the project's name as a tag to a brush and have it appear in its corresponding project brush folder.