TPS2378: Class 4 minimum power requirement

Part Number:TPS2378

According to table 1 of the TPS2378 datasheet, the class 4 minimum power requirement is 12.95W. We have an application that "switches" between low-power (~5W) and high-power modes (~15W). As a result, we may not meet the minimum power requirements for a class 4 powered device at all times. We're not very familiar with the PoE standard - what effect will this have on our power circuitry?

Thanks for your help.

--Frank