Waller confirmed Shoot Out would now be aimed at the A$500,000 Epsom Handicap (1600m) at Randwick on October 6.
Shoot Out ran a close second to champion mare More Joyous in the Doncaster Mile last autumn and that pair head the Epsom weights.
More Joyous has 60.5kg and is almost certain to miss the race, which means Shoot Out will be topweight with 58kg.
"I think Shoot Out is well weighted in the Epsom," Waller said.
"If Shoot Out can keep winning, then we would consider the Cox Plate, but there is also a race like the Mackinnon Stakes that would suit him."
Shoot Out will attempt to join Racing To Win (2006) as the only horse to win the George Main Stakes-Epsom Handicap double since Imposing in 1979.
The tough 6-year-old scored his ninth win from 30 starts to take his earnings to nearly A$2.9 million.
Waller obviously took into account Shoot Out's record at Randwick when he decided on his audacious plan to run the gelding first up in the George Main Stakes.
It was also a reflection of Waller's confidence in his own training ability.
"When you are winning races, you don't get questioned as much as say a younger trainer does. You get the confidence in yourself to try things but a trainer only learns from his mistakes and I still make plenty."