Yeah thats the same info I found and the same conclusion I came to - though I can't find anything to confirm it. I don't really want to call QLD Transport as from past experience I will get a different answer each time I call
I might call around a couple of reputable trailer places. Not sure if it's something that is checked by a roadworthy or if they would even know.
Besides the legality of it though its bloody stupid... I only found out when I turned on the hazards on the side of the road with the van on the back! Every time I have tested I still had the engine running.