I would like to see this as well. However, it would have to be a secret setting somewhere, so that the new users don't automatically start uploading JPEGs of their vacation and wonder why the player won't play them.

In the meantime, have you tried messing with Hijack instead of Displayserver? Its install is simpler and doesn't require a downgrade. And if you still want to run Displayserver, you can send it to the player using the Hijack FTP features, no downgrade necessary.