TooLateMate mutator is an attempt to fix the way how the game handles with late joiners. Due the fact that this UT2004 leftover never fully worked in KF conditions I have taken steps to write a compatible mutator. The idea is simple, 20 seconds prior wave start (set by admin, above 5) all players from current game are being whitelisted and anti-latejoiner script starts to roll. From now on, any new player joining to the game will be automatically discarded from the current game session with appropiate disconnect message (see screenshot). Mutator is automatically whitelisted since TWI removed whitelist check some time ago. If you use MapVoteV2 you can add this mutator to selected vote options.
Features, installation instructions and more info can be found on Steam workshop page.
Can't copy & paste my description here :/