Need Course Mastery to automatically assign work to students in a school classroom.

As a high school teacher, using Khan Academy for Mastery learning is too much too manage. I would still have to analyze the level of mastery of each student and decide who needs which assignments. It will take several minutes per each of my 170 students. It's just not feasible.

I'm hoping Khan can create something that can manage a scenario like the following:

Assign a unit test or course challenge to a whole class. Then have the system automatically assign each student the lessons they need to watch and work on, based on their scores from the unit test or course challenge. I would still like the teacher to be able to see what has been assigned to each student and see their data from completing the work. Is something like this possible? If not, the course mastery feature is just too much to manage for secondary education, where we have so many students.