I used to fly out of an airport on the coast just south of the San Francisco Class B. While controllers tried to permit transit, there was no guarantee. If they also have a 91.131(a)(2) problem, that Miami solution would seem attractive to San Francisco. The result for VFR traffic on a trip headed north might be to add up to 100 miles or more to bypass the Class B to the east, or a deviation far out over the Pacific Ocean, neither of which is an attractive alternative.