In app builder please highlight calculation fields that get broken from the changing of a field name.

Often field names need changing after a calculation field has been created that uses that field. It would be great to be reminded that the calculation field no longer works once you've changed the referenced field's name. This could be by setting an message at the top or side of the app builder that says something like "Your calculation field references a field that no longer exists. Please update my_calc_field." Or maybe adding a highlight color to broken fields.