I’m a bad one to ask about parts editor because I rarely use it. As well it was not finished when development stopped, and is not complete, and I wasn’t involved in Fritzing til after development stopped so don’t know much of what was intended. That said, I suspect the idea is because the prefix is unique and I think probably partially time stamp based, that provides a way to keep generations of a part (much the same as git). I usually find parts editor annoying and edit the underlying files.
Peter