Mostly it would have been assets that are modified dynamically, programmatically while working in the editor but only committed once someone explicitly wanted to make the change shared.
An example might be something like a cache file, a global material.
Though it is understood to avoid this VC noise as much as possible. In any case I see that I can use Gluon and the main Plastic viewer on the same instance of the workspace so for now I'll just do it that way (switch tools). For some reason I thought I was unable to use the Plastic default Client on a workspace setup with Gluon.