You mean when both direction streetcar enters the tunnel on both sides, give priority to the westbound one first.True but they usually tend to space them pretty well on St Clair, usually the westbound one comes in first makes a brief stop to check the switch is set and then heads to the platform. The eastbound one will usually follow behind it and then stop to unload and load before going around the westbound one.
They would have less issues if they built the westbound platform directly on the straight tracks where the stairs from street level is located. TTC loves terminals and loops their buses and streetcars in big circles to just have everything in one spot. Of course that adds a lot of travel times.