The mass-storage you see is a fake mass-storage profile to trick the PC into providing 500mA to charge. Otherwise there is no way to charge for sure when connected. If you install developer mode you will also get an RNDIS device with ssh. Unfortunately mass-storage is a pain to work with and as such has not been retained. However it should not be insanely hard to get it to work with a fat formatted SD-card in the device.