The real culprit here is the CAA, which regulates HAL and sets service standards. The security queuing target is based on the time taken from entering the security area to getting to the baggage conveyor ahead of the X-Ray. The CAA has rejected proposals from various parties to set targets which measure the total time to pass through security, on the questionable grounds that the CAA has no jurisdiction on the security checks themselves (which are of course based on criteria set by the DfT).
Clearly the CAA's approach makes no sense, and it is entirely inconsistent with the CAA's statutory duty to prioritise the interests of passengers. As I have suggested on previous posts, please complain to the Economic Regulation Group of the CAA.