Same rule in Vic, containers must be filled on the ground.
Seems there is no easy answer, I am wary of electric pumping. The mechanical pumps might be a problem from my low slung 20 litre containers, I will investigate. Perhaps I need to find or fabricate a funnel that sits neatly in the filler and doesn't tip over, then modify the screw-on spout on the container. Ideally it would have a valve that I could open once everything was in position with the container sitting on the wing.
thinking further, a 10 litre can with a valve on the bottom that could be positioned on the wing over the filler would be ideal. Soft feet to prevent scratching the paint.