The visual of your brand's international presence is the first thing I picture here - and honestly, it's a muddled canvas. You've got this six-year-old .com dripping in North American sales juice, but now you want to paint the same masterpiece for UK, Australia, Europe... yet the .com.au domains are hogging the spotlight in Melbourne search results. That's a brand perception nightmare from a PR optics standpoint.
Here's what I'd consider: subfolders (/en-gb/, /en-au/, /fr-fr/) keep that precious domain authority you've slowly built with Google, Yandex, DuckDuckGo, and yes, even ChatGPT citations. The search crawlers see the same root domain - that's years of subtle reputation weight lifting. A new .com.au means starting from zero in the backlink department, and you've admitted those aren't abundant anyway. So you'd be sacrificing the one asset you do have: time-in-market.
But if the .com.au ranks purely because it signals "local" to Australian search engines, you could achieve the same with hreflang tags and region‑specific content on subfolders. Your brand's visual consistency (same logo, same tone) across all those folder paths actually builds a stronger aesthetic narrative internationally - like a gallery opening in every city with the same signature style.
Any PR or marketing resource I'd point you to would emphasise that domain age is a silent brand ambassador. Don't throw it away for a fresh start unless you've got a six‑figure backlink budget.
Does that help steer your research?