[Feature Request] Parallel downloading of videos in playlists instead of sequential

Not sure if this is just a limitation of the implementation and it's not all that big of a deal but it would be great if videos in a playlist could download in parallel in compliance with the max simultaneous video downloads setting. Would make downloading playlists and utilizing all the bandwidth available much more efficient.

Also unrelated but Andrew man bless you and your work because the update to the downloader UI is frickin' AMAZING! I LOVE IT!!!