144 Hour Visa Free Transit Question! So I'm planning on going to Shanghai on my way to Japan.

This is my current travel route: Los Angeles -> Hong Kong (layover) -> Shanghai (72 hours staying) -> Tokyo (9 days) -> Shanghai (10 hours) -> Hong Kong (layover) -> Los Angeles.

On this site it says: 'Key point: The international flights flying in and out of China – from A to B and from B to C – should be non-stop, without a stopover anywhere in Mainland China'

I cannot tell if this is a legal travel path, could someone please help?