Claiming a word as your own
The South Australians have claimed heap, as as in heaps good, as their own coinage. This seems a trifle extravagant in that there is evidence of the phrase having Australia-wide use in the 1990s as a colloquialism borrowed from British English and adopted by the young and cool. Skateboarders talked about skateboard ramps being heaps good in states other than South Australia.
For background on this see https://www.abc.net.au/news/2018-10-19/where-does-the-term-heaps-good-come-from/10071780
It is a development from the use of heaps to mean ‘a lot’, as in I love you heaps.
And that in turn came from the similar use of a heap as in She has a heap of books. The OED has examples of this use going back to the 1600s. So no special intervention from South Australia is required to explain this sequence that culminates in heaps better with heaps following the path of lots in being used with a comparative or superlative adjective.
I suppose the cool and catchy thing that heaps has done is to modify the base adjective. The phrase heaps good breaks the rules and is idiomatic. You can’t say lots good.
What did happen is that from 2000 on the phrase moved from teenspeak to more general slang, helped in South Australia by the production of a T-shirt with the outline of the state on a white background and the expression HEAPS GOOD running along the top. This performed the double function of making the phrase more mainstream and leading South Australians to associate it with their state.
It is interesting the way we build up associations with words or phrases that give us a special right to them, often expressed as a claim to original coinage. I am sure that there are Australians who believe that bushranger and fair dinkum are Australian coinages, just because we have done so much more with them than anyone else. (Bushranger was a borrowing from American English and fair dinkum from northern British English dialect).
Even at the level of the individual it happens. There have been correspondents to Macquarie Dictionary who claimed to have invented a word. Research usually proved this not to be the case. People can, however, feel that they have known a word for so long and it is so much a part of them, that it must have been their creation. I always felt slightly mean for pouring cold water over these illusory claims because the feeling of ownership expressed by the correspondent was obviously so strong and the attachment to the word so heartfelt.