The problem is not in the purpose built flats where there is proper compartmentation etc. the stay put policy should be fine there.
The problems come in the big houses that have now been converted into flats where the owners want a stay put policy because they don't want the problems with communal fire alarms and the purpose built blocks of flats that probably were ok when they were built, but have now been knocked about by electricians, plumbers, occupiers and the owners so that they have the compartmentation of a swiss cheese.
My view is if the compartmentation and MOE are not adequate, you cannot have a stay put policy. The owner has two choices either have work done to improve the compartmentation and/or MOE, or fit a fire alarm system and have a full, phased etc. evacuation policy. Either way the occupiers have to be informed of what is going on and what they should do. If the occupiers decide to stuff the sounders full of socks etc. then that is their choice and the outcome will be on their heads, provided the owners have maintained the system and can prove it.
What is wrong is putting a stay put policy into a building that cannot support it because of the problems with a communal alarm system.