OK.  How about `STUDENT_PASSWORD_ITERATIONS_SYNCED` and `STUDENT_PASSWORD_ITERATIONS_LOCAL`?  We'll use both in our code, but only put the 'local' flag in our docs.  *And I'll enforce a minimum on the SYNCED version.*

I would disable the Settings--I think it's confusing / hard to support too many options to users. Benchmarking can be done through the local_settings.py just fine, and we are already supporting editing that file through our docs, so I think it's good to migrate everybody there and support a single scenario.

As for the syncing scenario... I hear you.  From what I can see, not a big concern at the moment.  And if they're online... please upgrade anyway! :)

OK, will make these