AVURLAsset doesn't contain any tracks when streaming a .m3u8 stream, so it's not possible to insert a tap or add a mixer.
AVPlayerItem.asset.tracks should contain a video and audio track when AVPlayerItem.status == .readyToPlay.
AVPlayerItem.asset.tracks is empty.
This is only when streaming .m3u8. If the URL is a .mp4 file, it works fine.