Some explanation of the differing distances and times:
The official trailroute is 157 km (the official gpx file says 158): https://extratrail.com/en/utds-trails/ I ran 174 km, because I took some wrong turns and missed some markers. 31h18 is the time officially recorded by Legends Tracking with their tracker.
I started August 14 at 4am and finished August 15 at 11h18 am. Those are the correct start and finish times according to the Legends Tracking 'leaderboard'.
The tracker of Legends Tracking recorded everything from the moment I switched it on, even before I headed to the trailhead, so there are some extra minutes before my start and after my finish.
The Garmin file is from the watch I used to record myself. 29h50 minutes is the 'moving time'. The total elapsed time is 31h20m: that is the moment i stopped my watch after finishing the trail.