This CoriantTypesEnableSwitch (default disabled) enables fast State-of-Polarization change tracking on the coherent optical channel (och-os) on the line side of a pluggable transceiver, letting the coherent receiver tolerate very rapid polarization transients that would otherwise cause errors or a brief outage. An administrator enables this on links known to experience fast polarization events, such as aerial cable runs near overhead power lines or other environments prone to mechanical fiber disturbance. For example, enabling fast SOP mode on och-os after occasional unexplained error bursts were traced to wind-induced fiber movement would help the receiver ride through those fast polarization changes without losing lock.