From what I can see you only need to do three things for the Kit to work with 4.14
- Comment out or delete the last two public override parts parts dealing with MonolithicOnly in CleanThirdPersonServer.Target.cs in Source
- Change CommandChatWho in MMOCharacter to use Get Num Player function instead of the old way of grabbing the value directly
- Fix the cast to MMOPlayerCharacter for Try to Loot in MMOPlayerController / Right Click
Seems to play just fine after those changes.