EDIT: I must be dumb. The function is already there. Sorry for bothering the community. 
Today I’ve read over the arranger thread.
When thinking about the concepts I stumbled over the fact that there’s no one-step-way to make patterns unique. You can do this with cloning, but this will always insert an additional pattern in the pattern sequence and you’ll have to delete the “old” pattern.
How about having a “make unique” function?
This will work similar to clone, but will additionally replace the pattern in sequence you made “unique” by the new one.
Later on this function is also useful in an arranger view.
There could be some graphical indication in the sequencer that a pattern “is not unique” (used more than once in a song). This would be helpful so that you don’t accidentally chance a pattern that’s already used somewhere else in your song.