It's been a thing that has annoyed lots of organizers since possibly the begining of WBO. Players leaving mid-way through a tournament is very frustrating, but sometimes it can't be helped. Most of the people who leave most likely can't control the reason why and therefore must forfeit, which is why I don't see fit to punish them for such a reason. However I do have a suggestion to make things possibly easier. How about a sheet of paper recording everyone's check-in and check-out times? This way a player could write down the time they leave which could make things easier for the tournament. At the start of every round someone in charge would simply have to remove them from the tournament instead of searching for them and awaiting their arrival. Then, if a player is not present and did not sign the check-out sheet, they would be punished accordingly.