Separate out time planned for the task today from the total time for the task to be done. As it is, when I timebox the task to the calendar, it changes the time planned for the task. Almost all of my tasks are multi day tasks. Ususally I plan my subtasks so that I can get a subtask done in one sitting or one day, but since I can't timebox particular subtasks yet, this would be a great workaround. It could be expanded to show how many more days of working that planned time it will take to complete the task, which would be wonderful for helping with time budgeting.