Hello René,
in Joomla!, only published articles can be visible from the frontend. The 'futur' article feature was meant to be able to show articles as events. So you can see the publish_down date as the date of the event. Events show as the published_up date is in the past. That was what it was intended for.
But I do understand what you are looking to do.
I will look into my code and see how I can modify this behavior (have the articles show even if the publish_up date is also in the future). Now, I am not sure, when people are clicking on the link of a future event, they will be able to edit that article...
Please contact me through [email protected] so I can send you a test version of the fix I will generate for this case.
Thank you!

Thank you very much!
the future article feature was meant as a simple event viewer feature. The only way to make this happen is to have a finished date. Do you mean you need to see the articles AFTER the events are over? If so, this is not possible in this case. Once the published date is over, the articles get unpublished.
The only workaround I can think of would be to have 2 articles for each event. One that uses the LNEE feature to show future events (with a finished date) and one that will not have a finished date.
If you need more advanced features, I would suggest using a full blown event management extension.
Thank you again for your enthusiasm!