My dad is a pretty smart guy. I asked him about this:
1. 4.3 to 6 is a medium quake. 7 is major.
2. What would you rather have, stress relief throughout the structure or no movement at all followed by a massive slippage?
You have correctly assessed the situation
Californa is resisting the gradual release. Therefore, the release will be major. The quale will be the Bigg’un.
San Francisco? LA? choices, choices , choices.