The big unresolved question here is, who is the "appropriate CBP official" to whom you are supposed to declare prescription drugs? If you wait until after you have been selected for random secondary inspection at the kiosk, it seems to me you'd be in trouble.
The only alternative I see is to use the regular process--I guess you could stand in the crew line, and I'm sure the crew members will love that--and declare to the agent there.
We also haven't figured out how to make a departure declaration.