Thinking about this now, the only good time to use these indicator lights would be in an emergency where it would take too much time to swerve your head, thus you can look at your indicators and pray that there is nothing there while going around a sudden obsticle.
Also driving in bad weather, fogged up windshields, hard visibility situations where you aren't 100 % sure if nothing is there, this can be used as confirmation after checking the blind spot manually.
It would def work for cars driving without lights at night.