Okihara,
There are dozens of VH- registered Bizjets flying all over the globe. So what's the issue? There are VH- registered bug smashers in PNG, Philippines, Indonesia, Singapore.
Two considerations worth considering are; sheer cost when an airline ticker is cheaper, lack of Avgas, cost of handling agents, landing fees, navigation charges. I have been flying a N-reg in Australia for 20+ years under FAA 61.3...… Foreign registered aircraft operating in Australia will eventually require maintenance, there is a few shops with FAA approval of sorts, as well as PNG, Indonesian and New Zealand.
Not quite sure where the thread is leading ….