Version 1.2.0 was released on
Mirror columns as data sources
We've improved how Checklist reads data from mirror columns.
Since mirror columns cannot be edited, the Checklist view becomes readonly when using a mirror column as a data source and the mirrored item's title is shown above the checklist.
Also, if the mirror column reflects data from multiple items, the Checklist view will display a readonly checklist for each reflected item.