About nine years ago I sold Iberia, Air Nostrum etc. Tickets for a living.

It would be easy for the Airlines to filter out passengers who skiplagged too often in the past and either make it impossible for the Gate Agents to issue Boarding Passes or show "Do not issue Boarding Pass" warning ... knowing the Chinese people by now, they would follow the rule by the dot. Making it impossible to book with a certain passport/id card or FQ-Traveller card would be another option.

Amadeus, Sabre, Galileo and all the system might look like they are from stoneage or medieval times, but it is really simple to add that feature.

I give you one example CA VIE-PEK a couple of days before departure they sometimes sell the one-way flight for 600 EUR upwards. If one simply adds the Air-Macau leg PEK-MFM with an 11 hour layover in PEK the same flight as a part of the VIE-PEK-MFM itinerary is being sold for the same departure date for 300 EUR on the Air China website itself.

In general, be it a Chinese or an Airline from another country, adding HKG, TPE or MFM to the itinerary, or fly one leg via HKG/TPE/MFM currently lowers the price for the flights to/from China considerably.

E.g. British Airways VIE-LHR-HKG and back PEK-LHR-VIE can save 500-1000 EUR compared to VIE-LHR-PEK r/t. Mind you that PEK-LHR-VIE is only 400 EUR in Preminum Economy.