To limit the probability that a hold-open device will not release a door and maintain the integrity of the fire separation [in which the door is located] when there is sufficient smoke in the vicinity of the door to actuate a smoke detector, which could lead to the spread of fire, which could lead to damage to the building.
To remove the permission to allow door release by means other than smoke detection [as stated in Clauses 3.1.8.14.(2)(a) and (b)] in order to provide for prompt release in the case of certain doors.