I did some side by side comparison between LG L70 D325 (Cricket - with working button lights) and our LG L70 D320n system files last year (now all these backup files are gone due to recent hard drive data loss/corrupt) and came across "emotion led" in both of the device trees. But the emotion led was missing in our D320n build prop and some other files were present in the D325 system like some light frequency codes which were not present in the D320n. I did try to push all this to the system and enable it in build prop. But I found no success and came to realize that it was kernel related or maybe the capacitive lights were not present in our devices. Maybe some of our DEVs can help.....Fingers crossed and good luck.