While I believe Japan was not "cheated", and was hitting its limits by the end of the war, and the Russia could have easily done better against Japan, I believe there is at least one respect Japan could have done better. Japan, if it had superior operational planning, execution and generalship, could have achieved its OTL gains more quickly, efficiently and at less cost. A *potential* knock-on of this could have been to give them running room to keep going for further campaigns and demands for indemnities, Manchuria, Sakhalin or the maritime provinces.