The door open button does serve to clean the gene pool, but the Melbourne Citadis have a request mode and an all-open mode, which I'm not sure whether it's possible to select on the Sydney's model.
'Open on release' has been deliberately left off. Door opening MUST be requested by pushing the button.
This a, probably futile, attempt to increase the airconditioning efficiency.
This was tried with the C set and Tangara trains but Sydney commuters proved to be unable to grasp this concept.
The driver of the first public run (Departed CQ at 10:13, set 001 + 002) did announce several times, 'press button to open doors'.
The airconditioning doesn't actually turn off when the tram stops, that's the traction converter fans you can hear.
However, some of the units have an insufficient flow rate on the AC. The ThermoKing pods look big enough to be up to the task, so hopefully, they just need to adjust the fan speeds properly. They a probably automatic load sensing types similar to what are in the Waratah trains and some either need adjusting or have faulty sensors.