This was my immediate thought as well. Micros are wonderfully flexible and I doubt the 16 positions are hard limit. Certainly the positions don't need to have equal angle portions.
One reason to "quantize" the angles is to avoid too much searching or cycling by the algorithm. Even though you lose some small amount of efficiency, you save a lot of wear on the servo and debugging time. If 16 works, he can always flash a new program and try for something different.
90 degrees is better than zero for two reasons. First the servo or structure might fail slightly to leave some pitch in the blades. Secondly the tower and blade loading is lower.
Was their any comment on the inputs to the micro? Is it tacho, wind speed, or both? There is something to be said for doing tacho, current (AC and all phases) and wind speed. That protects against a lot of failure modes.