Gail Badner what are you talking about? This issue number has been used to track progress on all three branches !
Do you really want that overhead of creating different issues per branch, linking them and have later in in time back porting become an issue chaining nightmare ?

We all spent a lot of time on that issue, so if that process is put in place, please go ahead, create the new issues, track the branches and rewrite all commits with the new issue number, push the new branches and create the new PRs for each.

The project will not become a bureaucracy nightmare. We are too thinly spread for additional work with little value like that.