Slightly OT but sometimes I wonder if 'fast track' systems could be re-imagined or re-worked. In my thinking a fast track lane should be reserved for those that are by and large fast and efficient through security (i.e. frequent fliers for the most part). Giving fast track access to anyone who spends a few quid or is flying business or is qualified but travelling with a young family* (buggies etc) will render fast track very quickly not so fast and at times busier and slower than normal lanes (as most of us on here I'm sure are aware of in T2 especially).

I'm obviously aware that if you are flying business you would expect a preferential service and the airport authority makes money on these systems by offering them to the public so it's not an easy fix. Maybe 2 lanes, frequent fliers and others. Even just at peak times separate the 2 to ensure a smooth flow of frequent fliers.

*I'm not trying to cast aspersions on the OP's topic here on the rightness or wrongness of bringing children through fast track in the current system. I would be in agreement with the OP if it's a quiet time of the day then allowing kids through with adults who have access should be fine.