Since its a requirement that you have to submit your plans to QLD Dot for approval - I would think the Dot would have to know whats allowed and whats not.
That doesnt mean just any old Dot branch will know. Like NSW you have a dedicated branch that has the rules and regs. Ask in any old branch and you will just get a blank stair.
Having said that, I have never consulted the NSW RTA, I have always spoken straight to the engineer that I will have pass it, but in NSW you dont need to submit plans to the RTA beforehand.