It would be nice if you could set a Default timeline /Emergency time line, that would always be downloaded to the client so that if there is no content in the Campaign it will play that Default timeline until it gets new content to play.
That way you can avoid that total failure of having a blank screen showing no content.
or if anything just the ability to asign a video to a station, so that it will loop over that when there is no content to display.
Just a Little need feature that would make Digital Signage so much better.