Asked bank manager very nicely. Note, this was before the Royal Banking Commission, so maybe things have changed with stricter IP measures these days.
If you have a PPOR you can get lower than the rate I quoted, but I think only 5-10 basis points. Ask your bank manager nicely. They are allowed one interest rate "review" per year, if you're on the Wealth package. Might depend on how many products you have with the bank.