I work at a local public radio station. I recently came across WNYC’s audio player in their tweet and thought it would be cool to try something similar. I designed a responsive audio player to be contained within the player card iFrame. However, I am a bit confused as to whether something like this is still possible. The player card documentation says they are for “video clips and audio streams” and refer to “video and audio” players, but some forum posts I have read seem to suggest that audio players are limited only to soundcloud. Is this the case? Would a custom audio player ever be approved for a player card?