Power-over-Ethernet Regulator

I am looking for a Power-over-Ethernet Regulator but for 3.3V as I use a MKR 1000 board. To my understanding the one available in the SuperHouse webshop is only able to provide 5V. Would I be able to modify to out 3.3V? Or is there a good reason for it to not be available on that voltage?

The MKR 1000 uses a USB Micro at 5V. You could use the Superhouse Passive POE injector with one of these on the other end: