What is the problem that needed solving? What else are you going to use it for? .
It goes back a long time but the issue fundamentally is that the BBJ isn't really suitable for long range missions as it doesn't have the payload capability and no crew rest. There also is a limit of the number of extra pax you can carry. (This issue came up in the Garuda Jogjakarta Accident) All this disappears if you get a wide body aircraft. The problem in Australia is that you will be pilloried by the press if you go and buy such an aircraft, even though that is what is required. So the compromise was use the Tanker with a VIP plug in interior instead of a dedicated aircraft.