I have only once had to collect a UM (12 yr old niece) and was disappointed with the airline. I won't bore you with that, as it is not relevant to this route. But I decided that, if I had to collect a UM that I would want more from the carrier.
Fine about check-in by adult but, I want the airline to to ensure that the UM directly meets the collecting and adult, recognises them and goes to them willingly. Whilst this other carrier did a good job throughout the flight with the UMs on board (she said). Once they were through Immigration and luggage - they were told, "Just walk through that corridor and your family will be waiting outside." What if I had not been there? Delayed? A 12 year old girl would have been wandering in LHR T1. I have no doubt that she would have found the Information desk but - many children would not be able to do that.
Bear in mind that I am not a parent so have not travelled with children and am doubly anxious when transporting them on behalf of family or friends. I will tell all my friends not to send UMs on this particualr carrier again.
I thought that an airline ground rep would locate me, bring the child with them, verify my identity and ask me to sign a form. Maybe I was expecting too much? Maybe other carriers do do that?