Flooded type cannot accept as high a charging voltage as AGM or gel type batteries so I would set the charger at the lower voltage. My Blue Sky solar controller adjusts the voltage output from 14.0 to 14.8 volts and can provide a 15.2v output for battery equalization (applies only to FLAT batteries). The voltage output varies both with the type of battery and the temperature of the battery if a temp sensor is used (higher temps results in lower charge voltage being applied).
Odd that yours only has a .1v difference with the settings. I would check with the manufacturer if they are in the USA. It may be a typo in the documentation.