you start with a "do not", then give a "you can" and then give another "do not". resequence so the thing that you can do comes first, followed by the caveats?
why is only the last one given a "warning"?

You can add group configurations at any time.
After your course starts, **do not**:
- Delete group configurations
- Change a group configuration ``id`` value
provide a reason if possible: as theses changes will invalidate your experiment(?)