Option to Hide Now Playing in Some Apps

I had an idea for a feature, it would be great to be able to hide the Now Playing widget for specific apps/even websites. For example, I use Plex to watch a lot of TV, and the now playing widget is somewhat inconsistent which messes with the buttons I have set up there. It would be great to just have it not appear, as I know what I'm watching anyway when I'm on that app!