Can you long press the notification and disable notification for the app?
No, not completely. I tried that when I first saw the stupid thing pop up in my notification bar. It does allow you to remove the headphones icon from appearing in the notification bar, but it won't allow you to stop it from appearing in the drop-down notification menu. It shows up every time you plug in headphones and then you have to swipe it away. Sigh. :\
Thanks for the suggestion anyway!
