I don't know if someone posted this but fixed timing will only work if the motor manufacturer can't build motors that are within a couple of degrees, motor to motor and batch to batch. That also goes for the rotor strength, symmetry and stator resistance. At a manufacturing price of $25/motor that is very hard to do. A supplier going through 1000+ motors to verify this also takes time and time is $$$. If it could be done it would be fantastic but from my manufacturing experience I know it would be very tough.
Not raining on the parade, just pointing out the reality of mass manufacturing and the tolerances needed to make us happy.