NVidia Shield owner here with a 2 year old...
I'm SO sick of my recommended videos being bombarded by Blippi and Cocomelon and my wife's music.
Is there ANY way to switch easily between YouTube profiles? Maybe even a 3rd party app (I've seen Smart YouTube, does it have this feature)?
I'm desperate.
What? You mean you don't want to watch Blippi without your 2 year old?
Use Smart YouTube TV. You could switch between profiles, like, in couple of clicks in that app.
I have a different solution than what others are suggesting. I use the restricted profile setting in android tv. It gives a completely separate second profile which you can also block apps. So in the restricted profile they can log in with their account. Or in my case I block YouTube and allow YouTube kids
Try FireTV Version of youtube. It support multiple account and it is independent from any Google Service
https://drive.google.com/open?id=1GTodW-ZxK_yShmqWHgFlv8-nhe_kMJDD
You should be able to add multiple google accounts in device settings @ accounts, afterwhich you can switch between those profiles @ the YouTube app.