I have always found most US mainline carriers helpful when it comes to schedule changes or tweaks on my end. We had a delta connection and asked at the gate if they could move us to the earlier one, wasn’t an issue. We had storm delays at a connection point on one flight so I asked if they could re route us via somewhere else, all done no issues and no cost. I find the technology platforms used, websites and apps, especially Delta, top notch.
Executives down under have one clear task, to rip as much revenue from every single soul as they can. They will only look after you if one has a whinge and it makes the local newspaper. Expect a phone call within minutes to resolve.