Hi ap 797
I think the following may be up to date info you are looking for !
If you are successful in stage 2 & 3 and again in flight grading at FTA Adelaide, you are then offered a position on the S/O Cadet course. En-route to Adelaide you attend a Pre-Course Briefing and Cadet Orientation Course in Hong Kong, it is then when you have a class 1 medical.
Hope this is helpful.