The only way to stop pax taking bags off in an emergency is to stop them bringing them on in the first place. Good luck with that.
I often wonder what people carry across the world with them! If your going to a warm place you only need T shirts and shorts!!
Two words, Air conditioning!
The RAF had a box and if your hand carry dint go in then you had to let it go in the hold ,also no more than 4 kilo was allowed,talking transport command now.So why do airlines let people carrry on huge holdalls etc ,so they can just by-pass the carousel?Time to get serious,I was amazed at the pax on that EK crash !!!
A similar system operates in UK airports, but the box is a bit bigger and the weight is not an issue unless you can't put it in the o/head bin.
The trouble is that if your a low paid check in agent faced with a a huge queue of irate passengers who are giving you grief about the size of the 'box' and they refuse to put it in the hold, what will you do, ignore it or ruthlessly enforce the rule. Responsibility then passes to the cabin crew at the door who again try to stop passengers with oversize bags from boarding. Result is a delay and managers not happy.