I have some basic timeline functionality working, as well as attachment uploads. I have AAC audio in an mp4 container, if I upload it as video/mp4, tapping the card will playback the file with a blank video icon. When uploading as audio/mp4, nothing happens when tapping the card. I've also tried substituting an MP3 and using audio/mp3, with the same results.
Is audio attachment playback not working yet, or am I missing something here?
Ideally, I'd like to show the HTML template card, and have the audio playback triggered from an action.