dont be surprised old friend .....its a BMW they all do that. Its proberbly the first of many visits to your dealer for warranty work.
hope you can still enjoy riding in a great country
Did you contact BMW to report this as a fault, if so what was there response?
I have a small amount of corrosion at the same location (starter motor mount) looks like an easily replaceable part. My bike is 5 x months old and I haved used it throughout the winter.
I dont know whether to report this or just rmove the corrosion and give it a proper coat of paint.