Sorry I'm late, I missed this thread...
First bit of info is that these approaches are not Airservices, they are a 3rd party so this info comes second hand.
You will note the RNAV-Z 12 is not authorised for CAT D aeroplanes. It complies with PANS-OPS wrt to the criteria but is unflyable for CAT D aircraft. Was tested in a 747 sim, and found that they could not get stable for final approach.
That being said, the alignment criteria is max 15° offset from the CL, but cannot cross the CL any closer than 1400m. I don't know what the CL crossing distance is but with Oakey so close to the north my guess is that it would be at 1400m. This crossing point is also the common location for the missed approach point. This was the only way they could design the approach without requiring an exemption from CASA MOS173.
A lesson here for CASA...in complying with your bulls**t rules, you have forced the outcome which is that in order to comply, the procedure is unflyable. The only procedure that is flyable is unavailable most of the time. The airspace containment and separation criteria is a joke...
The RNAV-Y is the preferred approach (obviously) but has issues with Oakey....it got political in the end.
Alpha