https://xod.io/libs/gweimer/servo/
Trying to control servo from multiple patches in a state machine was not working with standard servo. This was my solution to fix the problem.
servo-enable: Standard servo node with Enable pin added. Detach servo when En is false and allow to free-wheel (or allow other node to control the servo).
servo-pulse: Merge servo and delay nodes to activate servo just long enough to move to new position based on previous position. Detach servo when timer is done.