There is a catch-22 making this really difficult. Have you ever sunk out to the beach at your CA cliff sites and noticed no wind down there?
Sadly I have. Once in my 115 lb rigid wing.
Steep hills bring the lift band laterally close to the water, but mainly high overhead. The lower areas stagnate. Versus a laminar area like Marina where the lift band is low but set back far from the water, and at a challenging L/D angle (fast horizontal and slow upwards).
I agree areas like Funston or Torrey Pines would likely be pretty tricky. I think Marina might be doable as we actually launch directly from the (sloping) beach frequently. Don't even use the launch ramp or ridge. With 100' lines I think I could put the kite in the lift band fairly readily. But I do worry that you might just swing yourself into the "cliff".
At Marina people soar all the way down to the sand and back up, so I suspect it would be doable in the right conditions.