There's no mention of reboot needed on the man page:
Sets the maximum number of concurrent commands that can be dispatched to any target port on an external RAID array. This is useful on V-Series systems, which support large numbers of LUNs behind a single device ID. If too many commands are issued the overall performance of the external RAID array may be degraded. A value of 0 indicates that no limit is enforced on any target port.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff, Sr.
Independent NetApp Consultant http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, FastLane US http://www.fastlaneus.com/
(P.S. I appreciate 'kudos' on any helpful posts.)