I'm not a fan of how when you cast to YouTube, it hijacks the entire device to open the Chromecast built in app. For example, you can't connect to the Android TV (mibox, shield, they all do it) while you're watching a different video. On my LG Smart TV it will just pop up that I connected, leaving the current video playing. Between this, and the remote becoming almost useless, only recently getting FF/RW/pause functionality... seriously?? If you disable Chromecast Built In it will cast to the YouTube app, but I still like to be able to cast other things. Is this a crazy request?
Edit: here's the scenario. You and a few of your friends are watching YouTube on the TV. You picked a video to watch with the TV remote. Half way though that video one of your friends wants to queue up a different video, so they connect (from the YouTube app on his phone, cast to the TV) but boom, instead of a little subtle banner that says "John's Pixel has connected", it completely boots you from the YouTube app to open that stupid "waiting to cast" YouTube screen.
Lol sorry for not wording this in a cohesive manner
You cast to a tv, not youtube