the threefold repetition only occurs when all players (including the disconnected player) repeat the position three times
so if you perpetual check red but green moves his king from one side of the board to the other then you will never get a draw by threefold repetition, but you will get it from 50-move-rule.
personally I think it's dumb how the threefold repetition draw rule depends on the random movement of a disconnected player's king but I guess it's there for a reason
https://www.chess.com/variants/4-player-chess/game/66751677
Can we claim a three fold repetition with three players when one has disconnected and the other is in a three fold trap?
Or would blue (in this game) have to keep checking for 50 moves where it would be a draw after 50 moves due to no new captures?
Or can it never be a draw in this game?
Thanks