Overhead lockers... locking ?
One solution might be a dead bolt locking system on all pax lockers switched by the crew on Declaration of an Emergency Evacuation .
There will obviously be a few gotchas but if the Captain says Immediate Emergency Exit then that is his call...
CC override might be an option. And of course there's going to be a weight and complexity issue.
e.g. do modern airliners have pax. visual message placards that light up saying Immediate Emergency Evac ? Or audio like a fire alarm (but not noisy and panicky) but instantly recognisable.
No they don't... wouldn't this save CC a lot if grief and time in such critical emergencies if at least the majority knew WIHIH ?