Given that this particular A/C was successfully evacuated despite people taking their luggage with them, maybe a separate thread on evacuations and luggage would be helpful?
Clearly simply wiring the locks to the seatbelt signs won't work. The general point is that if people can't access the overhead bins in an evac, and if they know this from the safety brief then perhaps they will concentrate on getting from seat to slide as quickly as possible without wasting precious seconds rescuing of their ipad and duty free.
No more from me, and thoughts with those who were unable to walk away from this.