I had a similar issue last year when wanting to buy on Red Days...

I had a similar issue last year when wanting to buy on Red Days but having no funds in my Trading Account which took days to receive.
I did a little investigating and now have instant bank account to trading account transfers.

Do you have PayID or similar set up with your bank?
I could not do this with my Offset account but i created a Savings account with this feature (all on the ANZ App).
I simply transfer funds from Offset Account to Savings Account and then Savings Account to Trading Account.
The funds arrive within 3mins and away you go...
If you want to adjust your transfer limit, you will have to log into ANZ on Desktop.
I assume its the same or similar with other banks.

NOT FINANCIAL ADVICE - This is just an option for quick fund transfers and I am not recommending it especially if you dont have the right temperament for this game.