Central locking on the overhead bins? Sorry, but on which planet do you live?
Apart from trying to put their stuff elsewhere etc. etc., some pax will inevitably fail to notice (or will have forgotten) that the bins are locked and will try again and again to open them, thus further delaying the evac. As
e1229 aptly put it:
Try to understand why PAX do that, and act properly
i.e. design evac such that it is taking account of human behaviour. Ultimately, this means wider aisles, less seats....
On a different planet, too. I know.