Client, Common, and Server I think is being misinterpreted between logical and physical. The configs refer to the logical side. When deciding between common and server configs on the physical side, the Common/Server configs take precedent on the physical server while client configs will take precedent on the physical client only. In your case, configs are world save specific on physical servers since only one config is available for any one physical server. Physical clients will have one config for many worlds since its all hosted on one device.