I'm with ps1 on this issue. They are important, yes. It's important to do things properly as to not get injured. However, banging away at rep after rep of breakfall from a position that you will hardly ever take a fall from is an exercise in futility. Do a few, keep tuned up formally occasionally, and make sure that you or your students are conducting them properly during rolls, sparring, drilling, ect. Include it as part of the debrief on a match, ect. That will have far more effect that slamming yourself to the mat again and again.