Back when I was SE, the concierges helped me as follows:

On a booking SYD-YVR-YEG with my wife, originally needed a longer layover in YVR. Things changed and we needed to get an earlier flight YVR-YEG but earlier flights were full and the check-in agent was not able to do anything. Spoke to the SYD concierge and when we got to YVR the conceirge greeted us at the gate with new boarding passes for an earlier flight. IIRC she also had new baggage tags for us to apply to our bags once they were picked up in customs.

On a booking YEG-YYC-PHX (one of the few times I travelled within NA with checked bags) my bag did not show up at YYC at US customs. Concierge went down to baggage to see if the bag could be located.

There were a few other things they did for me that were quite helpful too...