I don't think that you can get direction from the switches. Maybe from the non-derail part of the switch but that's internal; not available from the posts. That would give you the trigger for direction just like any other isolated track detection method.
I would skip the switches and arrange block detection for the direction that you want to NOT stop the trains; Westbound. The block occupancy detector would activate a timed relay that would put power to the "stop block" of the 253 signal. The timing interval would be enough to let the train pass through.
Eastbound trains would hit the stop block and the 253 would behave in the normal way to stop the train. Then when it continues, it will hit the trigger section but that doesn't matter; it's already past the stopping point. When the timing cycle is complete, the relay is deactivated and the sequence is reset.
