Is there a NEC reference allowing or not allowing a local motor disconnect to locked in the energized position?
Motors and wiring are protected at the MCC for short circuit and overload. The location of the local motor disconnect is inadequately protected from the public.
The disconnect is there as a means of locking it out for servicing. It has no emergency functions at all, even though some people tend to use them that way. I don't believe there is any general prohibition against locking them in the closed position to be found in any standard that likely applies.