When my parents flew from Europe to Seoul via PVG, they had to exit to landside and do the whole sequence ( health form, check-in, security and passport control ) to get to their MU gate. Dad as an old China hand had fixed multiple entry visas for both and as far as I understood this did at least make things a lot easier.

They were travelling with hand luggage only and according to what mom told me might not have made the cut otherwise. Of course the MU flight was an hour late after all, but that's a different story...