144 hours transit visa, MelbourneShanghaiFrankfurt

Hello, in November on the return flight from Australia to Germany I will have a stopover of 2 nights in Shanghai each nonstop flights. I have booked all flights online and the flight from Australia to Shanghai is with another airline like the flight from Shanghai to Germany. Therefore, I have at the time of entry in Shanghai for the onward flight to Germany only an eticket number and a printed confirmation, because a confirmed seat or boarding pass I will only get when checking in for the flight to Germany 2 days later. Is the eticket number and a printed confirmation sufficient for the 144Hour Free Transit?