The only known issue of this civilization, discovered by NighttFury, is related to the feudal Town Center. Building this Town Center takes longer to build than regular Town Centers (270 seconds against 150). If you reach Castle Age while the feudal Town Center is in process but the villagers have worked on it for more than 150 seconds, it will build automatically. However, since buildings gain HP as they build, the Town Center will not be at full health. So far I haven’t found a way around this.