In the rules Cheats have to be on. for the video proofer. The person recording can see commands and probably can't spam F4+D fast enough to not, and chat must not be hidden stated by the rules (They can see that when you use /time set 0 at the beginning). But /locate is one command that doesn't show in chat for people who have not typed it. I would say the solution to this is to require to shown the server log after the run. I would also think that /locate Stronghold isn't that much of a cheat they need eyes for the portal. But if they haven't thrown any eyes than it is kind of obvious that there are cheating. I don't think people would try splice a Co-op run though.
The world is just a layer of stone with one cobblestone in the middle. Edit: I copied the world file so I used the Original and it Works!
Why can't 6 Day or less delete your run. It seems to have no purpose and I can't remove my run that I now think is invalid.