Piping Google Hangouts notifications to headphones

I'm on the fence for buying the app, see if you can help me figure out how to get the functionality I want out of it:

I'm trying to keep headphones in at work and have 100% of all sounds piped into the earbuds. Google Hangouts is the most notorious offender. I want to be able to get audible queues to messages including hangouts, work e-mails, gmails, calls, texts, etc, so I don't have to look away from my work to check these various portals.

Instead, with SoundAbout freshly installed and "notification behavior" unchecked on both boxes, hangouts is playing in my earbuds AND on my phone speaker.

If I set the phone to silent or vibrate, it overrides the headphones notifications.

I'm running a Verizon GS4 stock.

Try the latest beta version here:
https://soundabout.forumotion.com/f8-download-beta-versions

If that doesn't work, then what is most likey happening is that Google Hangouts is controlling where it's notifications are being played and also making sure those audio outputs are available before playing the audio. If that is the case, then it is overriding anything SoundAbout is trying to do. There is no way around it other than the central silent or vibrate modes.