tournaments is pretty easy to make, just requires a lot of fine tuning of certain details. you just need to create match script objects that hold the two players and a bracket script object that holds all the matches. a list that holds winners and a list that holds losers. a round ends when there are no matches left and a round begins whenever you tell it to, which creates the matches.
a match is lost when one player dies or leaves the game. you can also make it so that if a match tries to start with one player it will just declare the player an automatic winner (since there's no competitor. useful for when the winner list isn't even)
all the maps for tournaments were pre-built and cloned so that there would be 16 maps (or 32 once the bracket size increased) and you can easily use named bricks as teleport points. so you can make map script objects too and give it a name (or selection chance) and then a list of the two pairs of spawn objects. so if i made a map like stonehenge i could make 2 copies of it and name spawns for the first one stonehenge_00 and stonehenge_10 and for the second map stonehenge_01 and stonehenge_11, etc... with the first number being which of the two spawns it is (0 can be player 1, 1 can be player 2) and the second number being which clone number it is. this is basically what gyt did.
a losing bracket is optional but its basically just another bracket object that begins once the first round has ended. all the losers fight and once the losing round ends, it will wait until the winning bracket's second round was lost so all the R2 losers of the winning bracket can fight against the R1 winners of the losing bracket
since this is all script objects you don't actually need to test this out with actual players. you can easily just create fake dummy player object substitutes using your own scriptobjects and simulate the entire bracket so you can test the entire workflow of the game. once you've nailed the simulated tournament you can basically just insert regular player objects into those spaces and the game will run like a charm.
the main reason gyt didn't want to release it or work on it again is probably because he brute forced a lot of the project so it would be hard to read to everyone except him. im sure he'd have to rewrite a lot of stuff if he was going to release it just so it would be barely readable.