it would be great if plex download the music videos as that would allow people with not very good Internet connections to use this feature as well as generally increase the responsibility of the server.
If you are talking about the music videos that are automatically added by PMS, this is not possible. Those videos come from a paid provider and Plex’s license only allows for streaming, but downloading. I’m guessing the source also is only allowed by the video producers to stream and is not allowed to let their customers download the videos.
