So, I Realize this post is 2 years old, but I tried this out on a CJMCU Beetle (not to be confused with the DFRobot Beetle) and it, well, does not work.
I guess my next step is to figure out how to re-program the 32u4. The only things i changed were the pin numbers, since the 5 and 6 aren't brought out to through-holes on the Beetle. Maybe the pin assignment is different on the (allegedly leonardo compatible) beetle than the micro.