I don't think it's going to change much; unfortunately, unfocused security is part and parcel of "the new security arrangement". Someone once compared security to religion; good idea in principle, but the things done in its name ...
I suspect that the transit via HKG will gradually (even quickly) become more popular than LAX, in which case NZ will probably swap acft, putting a -400 on the HKG route and a 777 on the LAX-LHR route. Perhaps they could even swap airports and have the LAX route originating in LGW?
I doubt if the Americans will care that much one way or another and I doubt it will change their behaviour. The man hours spent in getting people to go through Immigration and jump through all the hoops when they're not entering the country is not just wasteful, it's irresponsible and ultimately, does absolutely nothing to improve security. In any case, doesn't ANZ have to provide lists of passengers, like any other airline, so if the US authorities have this, what exactly is the point of subjecting tired passengers to this rigmarole. Surely there are considerably more pressing and important duties to which these officers could be assigned? (No rude suggestions now ... well, not too many.
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