For anyone else more interested in the climbing wall, direct link to their climbing page: https://www.copenhill.dk/en/activities/climbing
On the other hand, I can think of a multitude of ways of providing multipitch top roping in such an environment. Joining two ends of a rope and running it through both anchors would be fine. You could even use a series of autobelay devices with retrieval tag lines to keep things relatively simple (though arm destroying).
> only experienced and trained climbers are allowed to climb to the top.
I wonder if they really mean allowed, or actually mean capable