Unfortunately Versions apply to the entire project, so I would need to create new projects for each unique add-on and then give some one permissions to manage the Versions in the project for them to be truly useful. Which is what we may have to do. Let me go through the Jira documentation and see if I can find any alternative ideas first.
How could I use the fields Affects Version/s: and Fix Version/s. They should be usefull but they are for the moment not editable. How could I change that ? Any ideas ?