Native commands in Google Action for streaming block

Why is there no Previous or Back option when using the streaming block for a Google Action? Yes, I know it shows in VF, but it doesn’t seem to work that way in our Alpha. Even testing Pandora on a Google Mini, it does not recognize Back or Previous. Thoughts?

Also, unlike the streaming block for Alexa, there is no Previous section. You only get one link. What’s up with that?