I have found at smaller stations where you are likely to deal with the same agents over and over again, it is best to try/attempt to follow their "wishes". Chance are that, at some p0oint, you will need them to do a "favor" for you. That said, you could write in to DL and they will follow up with the agents on the exact rules. In general, the GA's job can be stressful during the last 20 minutes before the flight departs. Anything to reduce that stress is greatly appreciated.