We have completed the checklist feature as a solution for this.
Here is a related thread if you’d like to support or follow the suggestion for assigning checklist items: https://planner.uservoice.com/forums/330525-microsoft-planner-feedback-forum/suggestions/14924745-assign-checklist-item-to-specific-individuals
An error occurred while saving the commentAnonymous commented
Unfortunately, checklist is not sufficient without having due dates for each checklist item. Would you please integrate this into Planner.