Security pah !
When I bought my last car I had the default alarm upgraded to the best spec prior to collection without checking what the difference was, assuming this had to be a good idea. Mistake.
The additional function seems to be to arm itself unbidden when one is trying to load the vehicle, result in the damned thing going off simply to annoy: and necessitating having to leave the keys in the ignition for the duration to prevent it doing so.
Much more secure.