I’ve done some work on the eVc firmware to allow for firmware upgrades over USB. This will allow for additional features and eventual bugfixes to be implemented by the user themselves. Current devices can be upgraded to support this feature as well, but requires an Atmel AVR compatible programmer. I can upgrade your device(s) for the cost of shipping, or perhaps if you bring it to me during Computex 2014.
The device enters firmware upgrade mode (USBasp compatible) through shorting the SDA and GND pins of the I2C output during reset (simply put a jumper and replug the device). This is supported through the implementation of USBaspLoader (http://www.obdev.at/products/vusb/usbasploader.html) using the forked version by Stephan Bärwolf (https://github.com/baerwolf/USBaspLoader).