@FlightDetent
It helps if you state whom you (dis)agree with.
The HNA contracts are between two parties; the agency and the pilot, HNA is mentioned in the contract, but only as the service airline and is not a signatory. Only the two main parties (agency/pilot) sign the contract. At least in the 2017 versions. The service agreement is strictly between HNA and agency, you don't get to see that one....
Some 'agents' are only intermediate parties where they get a onetime finders fee, then you end up signing with HNA's own agency which is a separate entity and located in HKG, others are real agents which you sign a contract with and are employed by them.
Since the beginning of the 2018 I believe they have a NTR transition contract which is a tripartite (HNA/agent/pilot) contract concerning and limited to a training bond. That goes together with the individual contract between the agent and the pilot.
Th individual countries implement the different treaties their own way, but from a strict legal viewpoint this is what you get. And yes paragraph 3 of art. 15 usually allows the other state to collect the taxes where the home state can collect any surplus.
Btw it's the first time I've seen a good conversation about taxes, which is an important issue fn decision making wether to go the expat/china way.
Many people just throw something in what they might have heard or think to be true, but if you just dive into your home countries tax treaty it is not that hard, though it usually means that you owe more taxes than you would like
