Hosting it in the UK would come with the risk of a hometown decision - which some, most notably veteran boxing personality Lance Revill, believe helped Parker against Ruiz Jr - going against the champion.
This is the point Duco have reached with Parker, where every decision on his future carries huge risk-reward implications.
It is also the sort of the small-fish-in-a-pool-full-of-sharks scenario that former Duco CEO Martin Snedden fears will turn Parker's head.
"Yes, that is a risk," Snedden said, when asked whether Parker will soon feel he has outgrown Duco. "Up until now, the fact Duco is a small Auckland-based company operating in a big, wide world of boxing hasn't mattered too much, because he's in the rising part of his career."
Snedden was convinced Parker wouldn't renege on the remainder of his contract, which expires in 2019, and is hopeful he'll recognise that he can achieve everything he wants to under the control of Duco owners Higgins and Dean Lonergan.
"One of the strategies recently, joining hands in a promotional sense with Bob Arum at Top Rank, was to connect with the biggest promoter in world boxing and by doing that, start to demonstrate to Joseph and others that there was no downside to staying connected to Duco."
Snedden said it was impossible to conceive that Parker would have risen through the ranks so quickly were it not for Duco's "heavy" investment in his talent and the training skills of Kevin Barry, faith that is really only starting to pay off now.
"For Dean to have the skill to get right in the middle of these boxing organisations around the world and basically persuade them that the best thing they could do was to give Joseph the chance to fight for a world title ... that in itself is an extraordinary achievement."
Snedden estimated Parker was about halfway through a career that was destined for a few more twists and turns.
"I hope it ends up being a good story," he said.
"I would hate for Joseph to end up in the same place that so many other boxers end up, where the money comes in and goes out, and they end up regretting it."