According to the UDS documentation, the "max" parameter for a GET to the /users node "[m]ust be less than what is specified in Enterprise Parameters, User Data Services, User Search Limit Setting."
In my experience this is incorrect. If you request > than the max, it will simply return the max.
This should be updated; as written, it sounds like the query should fail.
Badly worded in the documents. You can ask for more than the max, but UDS will return the max. It was designed so that your request will not fail because you may not know what the max value is.