The bridge is at 6nm, and if you believe in 300ft per NM, then the "correct" height at the bridge is 1800ft, not much difference. The base of class B goes to 1500 feet at 7nm and 2500ft at 10nm. The plate does say "recommended", not "required"
You're almost correct. 6NM is from the SFO VOR. The VOR is located at the crossing point of the runways. Not at the threshold. So you essentially lose another mile. Therefore 1500 feet at the bridge would equate to a 3 degree glide slope.
I know it's a small point, perhaps even nitpicking. I've seen FOs cross the bridge at the 1900 foot recommended altitude and they're one dot high on the GS (when there was a glide slope). Do you think the Korean crew would see that 1900 altitude as a 'recommend' or would they consider it a restriction ? I think they'd consider the latter.