Good news all, you can now filter by Progress using the “Filter” menu across all views, including the Schedule view.
Currently this is only available in Planner Web, we will enable in Teams next.
An error occurred while saving the commentMark Curtis commented
This gets my vote too and once the task is completed if it could be colour coded to indicate the task has been completed on the calendar that would be good too. This would make the calendar feature really useful.