This is also the leading explanation that I have been presented with.You are all putting way too much thought into this. The festival center and misplaced center lines have nothing to do with Harmonious being off center. It’s entirely because they choose to use existing infrastructure in the lake and were too cheap to move it. The L shaped structure in the center of the lagoon seen in your map was previously used for the earth globe and is now used for the harmonious center barge. Since the Harmonious barge is significantly larger it pushes its center further off center.