As a side effect of researching how to access the G13/G15 (Z10/G510) hardware on Linux and OS/X, I’ve implemented direct hardware access to those devices in LCDSirReal 2.8.4. If the Logitech software isn’t installed or running (or if it crashes), LCDSirReal will access the LCD directly. In addition, the G-keys will be translated into different special key codes not in common use, so you may be able to map them into games (unlikely unless it’s a quite clever game designer) or to macros using software like AutoHotKey. Yes, now you no longer need to run the 100MB+ Logitech software just to run LCDSirReal. Woot!
Download LCDSirReal 2.8.4 on it’s homepage.