I recently asked my students in a Financial planning class to upgrade their models in order to enjoy the timeline magic.
The experiment has been successful, but we encountered an issue from a behavior I had already noticed when the timelines were released for the first time: when one deletes a timeline category linked to others in the same model, the deletion propagates to all of those linked timelines. In order to prevent this sort of “mass destruction”, one has to unlink the timeline category before deleting it. But it’s easy for me to forget that step, and if I do, soon I am reminded by a flow of error messages lamenting broken formula references everywhere. I would suggest to unlink by default a timeline about to be deleted. That would make timeline deletion consistent with deletion of ordinary linked categories.