I don't know if I understood how this cup will work. But I think I will join it. I know it can be considered a bit unfair to add a scheme I created and not many people know, so I would probably have an advantage, but I would like to see people playing on a scheme I spent many time developing and I think it can be good for competitions.
I really would like to choose Boom for Weapons, but it is more complicated to play in competitions, since there are maps where you can get stuck if you don't apply a subjective rule. So it is a scheme that would be better if played with a referee judging when the rule will be applied. I could be considered not ethical if I judge while playing.
So, I will pick
Flat Earth Apocalypse. I recommend playing a few games of this scheme offline and alone before playing it with someone else online, since it is short and fast and if you don't get used to it you can die pretty soon in a game.
Ah this scheme can be played in 6 players even in competitions I think. It has only one required victory, but I think in competitions it is better at least as bo3, because it is a scheme with a good part of luck involved.
EDIT: I would like to pick Plop Gum too, but the scheme available here in TUS is not the same of the one available in HostingBuddy, and I wanted to use the HB scheme. And I will not upload a new scheme to TUS just with few editions to the one available in TUS.