Both Key Results and To-do have timelines that show 2 sets of data.
Status History
The status changes through time are displayed, plus optionally the due date for an To-do
Completed & Open Tasks
When the progress is based on completing Tasks in Trello, etc then all the tasks are also displayed on the timeline. If the task has a completed date or due date then they appear in the correct location in the timeline. Any task without a date is shown in the bottom left.
