Hi, would the 144 hour visa work in this situation:

1. Fly USA to Shanghai
2. 144 hour TWOV
3. Fly Shanghai to 3rd country (for example S. Korea)
4. Fly S. Korea back to Shanghai, stay in airport
5. Fly Shanghai back to USA

If yes, could you get another 144 hour TWOV between steps 4 and 5?

Thanks!