Using MSSession with MSMessageLiveLayout

I'm trying to use the new MSMessageLiveLayout with MSSession to create only a single balloon for a turn based experience, but i'm finding that the session gets ignored. When switching back to the old MSMessageTemplateLayout, the balloons behave as expected. This feels like a bug to me, but it's possible it's just not documented. Has anyone else experienced this? Is there a way to create the single-balloon experience I want with the new MSMessageLiveLayout?