Maybe I am being to much of a purist, but retroactively modifying commits and history? Why? Stuff happens, so do mistakes. Fix the mistakes, make another commit, and go on with your life.
Commits should be a contained change that can be understood as a logical piece of history, and reverted if necessary. If you have to look at multiple commits for 1 logical change to the code, it's much more difficult to figured out what the intention was, if it was correct, and how it can be reverted.
It messes up the team's ability to use tools like git-bisect to pinpoint behavior changes, and is generally more noise than signal.
At a bare minimum, those spans should get squashed before they leave the PR or feature branch.