My fellow respondents should be aware the question asks about Broad Australian (= ocker), not General Australian (= “neutral”).
I would like to think I’m General not Broad (as would any would-be member of the middle classes). People in California did have occasional difficulty with my accent; e.g. my pronunciation of Apple Cider coming across as Apple Soda. But I was pronouncing my r’s more often than not within a year (and whenever I’m on a teleconference with Americans since).
Can’t report any issues in Europe. Apart from my aunt in Athens, banning me from speaking English around her 7-year-old, so he wouldn’t grow up sounding like a hillbilly…