score:4
Youβre reading into words too much. Confirmed seat in this case means nothing more or less than a confirmed ticket.
Passengers with a British passport with nationality "British Citizen" with a confirmed onward air, cruise or train ticket* to a third country within 144 hours, starting from 00:01 on the day following the day of entry.
They must:
arrive at and depart from one of the following locations: Beijing (PEK), Tianjin (TSN), Shijiazhuang (SJW), Beijing West Railway Station, Tianjin International Cruise Home Port or Qinhuangdao Sea Port; and
have documents required for the next destination.
* The emphasis is mine.
Source: Timatic Via Emirates