In economics we talk about asymmetric information i.e. one side has information and the other side does not. Pre-megxit, while the rest of the royals and some in the UK knew that H was a hot mess, the American view was of the "happy cheeky chappy" Palace PR version of H. So H could sell himself in the USA to Netflix, Spotify and Penguin executives. You don't get to be an executive in these cutthroat tier-one companies without having some serious business judgement, so it actually a real credit to the effectiveness of Palace PR on a global stage.
Six years in, the information is symmetric. Aside from die-hard fans and paid trolls...it is evident H is a hot mess...he told us so in various interviews, and in his book, and in his lawsuits.
So, a move to Australia (or anywhere else) cannot reset the narrative because Australians (and indeed the world) can't unlearn frozen todgers and Elizabeth Arden creams from Spare, "We need to be able to say we had nothing to do with it" about giving info for Omid's Finding Freedom book, Mr. Mischief and G String "movie snuggles" from the latest lawsuit, etc. Moreover, the Sentebale lawsuit is outstanding with whatever gems come out of that discovery process. Finally, Invictus red flags could cover China's Communist Party plenary sessions for the next five years and more are still gathering daily!
IMHO, H&M will have the occasional royal cosplay grifters getaway, merch, speak at increasingly less prestigious events, appeal to Grandpa King Pa who is a billionaire and ignore Grandpa Thomas Markle who is not a billionaire. It will be a slow inevitable downward slide to oblivion.