That's currently how it's working for me in order that change profiles. It's a shame you can't switch profiles without having to exit the game.
Have you managed to get Xbox Live working for your apps by any chance? I'm trying to get it to work for my apps but all i can do is sign in. If i try to open leaderboard, it crashes for me and i get an error if i try to retrieve user profile.
I was wondering whether you've successfully got this working and could offer some help to get it working for me.