Originally Posted by Often1

Bringing printouts of TIMATIC or pulling it up on your phone and sticking it in some random agent's face is a poor idea and will not accomplish anything.

Arrive at YUL with a lot of extra time. If there is any difficulty, immediately have the agent call her help desk rather than wasting time. This is one of those situations where TIMATIC itself is not helpful as one has to enter the data correctly. If the destination is China, a visa is required. If the destination is Japan with a tramsit through China, TWOV will apply.