In answer to your original question about technical considerations to help them make the distance;
We are told that Qantas are going to great lengths to look at every item installed on the aircraft to see where they can save weight. Removing unnecessary galley fittings, light weight trolleys, this week they were even talking-up new light weight cutlery and crockery.
Qantas are also in the final stages of work on a completely new flight planning program. They had a university robotics team write the code to optimise the chosen flight path. It's supposed to analyse thousands of different route, level and speed combinations to find the most efficient route. It is far more advanced than the current system in use.
And then there is the fuel policy, ie. not carrying fuel for an alternate. (That's a well worn debate that I don't intend to revisit).
All these measures, and I'm sure many more, will help to make incremental increases to the range achieved by the 787-9.