Dustin, we will also be adding sensitivity adjustments in the software for using mouse to send keys/arrows, etc. (separate from the DPI - basically a threshold of sending a key every X pixels). The firmware is currently capable, but we just need to get the UI in place.
Another side note: we have updated firmware (internally) that we are testing currently which has the ability to program both master & slave devices as well as DPI settings. Hopefully testing goes smoothly so we can get it released soon