Override In-App LED Settings
I used to use Xposed to handle apps lighting up the LED by using GravityBox to set the default for all apps as "Off." That way I solely rely on LightFlow as the master controller of LEDs. Is it possible for you to implement a similar feature within the app where Light Flow overrides all other app's LED settings and becomes the master LED controller? The reason why I ask this is because currently Gmail lights up all notifications as white. Same with Hangouts. I'm guessing Google implemented some LED features in the app but doesn't expose it to the user. In order to disable those I need to set a specific notifier for Gmail and Hangouts in Light Flow to NOT blink the LED. That's annoying.
Expanding more on that point second bullet--for instance I want Important labels for GMail to light up my LED, so I set that notification up--but given that all Gmail notifications will light up white, a non-important email comes in and lights up my device and overrides the green LED for important mail. This is perhaps why Bullet #2 would be a nice feature. But in the mean time I tried to setup a notifier for ALL Gmail to be LED off, and have a second notifier for important emails to be green, and to prioritize it above the notifier for ALL Gmail, but it doesn't seem to be working.