when a valid configuration parameter is specified multiple times, later appearances silently override previous ones.
while overriding might be desired (think config file inclusion), being silent about it can be confusing.
it would be preferred to log repeated valid config parameters at debuglevel 3 (because they would only be logged upon startup and thus won't pollute the logfile that much, and also because non-accidental use is expected to be a minority).
repeated "UserParameter" options in agentd config file, of course, should not be logged, but repeating a userparameter key should. in that case it is also expected that latter occurrence overrides previous appearances.