Assuming this is going to work with mode recognition, it would be great if they lights can cycle colors based on what modes you've stacked. So if running Quorra and Gem, for instance, the colors would alternate green and blue, with some adjustable timer, 1s default, or even make left/right colors different while cycling through. The LE only keeps track of the color of the highest mode in the ladder, which while it does correspond to the music, does not convey stacking.
Can't wait to see the video of what you've got so far. This will replace the arcade mod as "best mod ever."