Sorry to bring this up again. We've now disabled the vanilla afk and it still happens, or at least this just did: Was in the ready room, listening to a discussion, not being marked AFK and received no warning. Suddenly kicked.
Server console reads:
[09:07:37]Client ATF[1136606] was AFK for over 7 minutes. Player count: 38. Min Players: 38. Kicking...

This appears to be the minplayers. People can be AFK indefinitely unless the server is close to capacity (that's how we like it). If it reaches 38 they get kicked as they have already reached the AFK time limit. Maybe re-check that part of the code.

Here's our config:

{
"IgnoreSpectators": false,
"MinPlayers": 38,
"OnlyCheckOnStarted": false,
"WarnTime": 4,
"MoveToSpectateOnWarn": false,
"WarnMinPlayers": 8,
"KickTime": 7,
"Warn": true,
"Delay": 0,
"MoveToReadyRoomOnWarn": true
}