to answer the original question, i have rarely spent more than 10 mins on the ground at YSBK, unless of course for said runway change.
On a busy day 10 yrs ago, you could be waiting behind 5 aircraft in the runup bay, but now, im usually to only one there.
circuits will take a little longer, especially heading to 29L but again, average just above 10 mins from start up to line up.