It is just a walk through to hand over cards at most, to keep people honest with their duty free allowances and declaration. Our last one around Willis Island on Majestic, we were given cards, filled them out, then shredded them we we got home. There was nobody to collect them, on what was otherwise a domestic cruise. Over the years, it has been 50/50 for us.
@Astro Flyer
Note that according to the Brisbane terminal page, arrival is 8am. If that is accurate, you have lost a bit of valuable time toward a possible late AM flight.
https://www.portbris.com.au/cruise/cruise-ship-schedule