Was told recently that the 1 piece rule couldn't even be overrided for Q staff. This was debated when I was about to be charge for it when traveling as staff from another airline.
you get charged excess baggage on Qantas if you are duty travel - really handy for engineers travelling with toolboxes - a few people got caught until we found out after you booked you duty travel, you had to email to ask for excess.
Jetstar is better - saw a Qantas link Engineer charged excess for toolbox and generator he was carrying to fix aircraft - management solution was engineer should use his credit card to pay - that was declined.
What happened to the good old days when I had a red tail busted upline, lob over to Ansett, throw a toobox and spares in the hold and get a seat upstairs - and the girls wold usually stick you up the front. Worked the same the other way.