Isn't SFO rather prone to delays (especially when fog cuts capacity by 50%+)? I believes that the reason WN dropped service to SFO (restarted them again recently for whatever reason which including warding off B6 and VX). It could also have been high fees among other things but delays resulted in slower turnarounds.

It was AS who started n/s YVR-SNA only to find out the customs error. I think only 1 flight ever did the n/s.