Several points: SF technically has a blade length limit, but it's seldom enforced except on the homeless. Because state law allows concealing manual-open folders (except for butterflies) they'll never need see your large Sebenza or even my Cold Steel Vaquero Grande.
The biggest risk would be the potential loss of an open-carry fixed blade. Something like a Mad Dog or my Outsider ($400 worth) would be moderately risky in SF, borderline insanity in Berkeley with similar rules but far harsher PD attitudes. Oakland is about halfway between Berzerkley and somewhat laid back SF. Your personal attitude, appearance, age and unfortunately, race factor into your odds of harassment or confiscation.
Even in a worst case scenario, you're not facing felonies over local ordinances. I personally broke one and was charges with an infraction that the DA dropped, I recovered two swords. So far as I'm aware, you're even safe from misdemeanors although a lawyer's opinion would be nice on that.
The next post is on a different subject, so I'll break here.
Jim March