I would like to be able to test my presentation without being blocked for more votes later on. Also it would be helpful, if I could test my presentation (with just nonsense/ fill-in comments) what it feels like to be bombarded with text and comments to get a feeling for time management in the actual presentation. Time management is extremely important in large events, so it would be nice to be able to test it.
Why not add a "test your presentation" button to see what it looks like.