To avoid creating projects labeled Part 1 and Part 2 for Agile projects, we could implement a feature to "park" tasks that are not yet confirmed or planned. These tasks would be hidden from the tracker, appearing greyed out to indicate their status. This way, we can still view them, but they would not be included in our workload balancer. This feature would also prevent the need to set all planned hours to zero until the tasks are confirmed.
