I'd like to know if there is a demand in Australia for a local crypto exchange.
And the chance of having one last more then a few weeks/months is almost zero, already knowing the outcome to many many previous attempts

Can you provide some links for information about this?
Why do you think one doesn't exist? Though quite a few have tried, and the current few that trade btc as a business do it via manual bank deposits giving the bank no connection to the btc trade.
You use any Aus bank to trade cryptos for fiat as a business, its not if but when all your associated bank accounts will be closed.