Being able to save a column as a templated column is a great feature to bring consistency across multiple boards.
However, when you need to update that column template, the option to edit does not exist.
Currently, the process is tedious and not efficient
- update your column design in one of your board,
- save it as a new template,
- add it to all the boards again
- re-assign all the label values to the newly added column template
- delete the former column template