If there is a more direct way to do this, I'd still love to hear it, but here's how I ended up solving the problem. I basically wrote a wrapper for LEDBlinky (Just an ahk script compiled as an exe) and had LaunchBox call the wrapper instead of LEDBlinky directly. By default, the wrapper just invokes LEDBlinky with the exact parameters that were passed to it. However, for specific MAME games that LEDBlinky won't light correctly, the wrapper changes the emulator name from MAME to "Direct" when it invokes LEDBlinky. In other words, instead of seeing "9 balonfgt MAME" LEDBlinky sees "9 balonfgt Direct". I then setup an emulator in LEDBlinky named "Direct" and configured the mappings for the games I need this for. Since LEDBlinky doesn't know the game is a MAME game, it doesn't attempt to map the buttons through the games config file (which it can't do correctly in any case), and I'm able to directly configure the buttons to light just as I would for any other non-MAME game. Hope that makes sense. It's a lot of hoops to jump through for something that I would have thought LEDBlinky would have allowed me to do directly, but at least I now have the right controls lighting up.