Manila Airport is the biggest let down of the whole Philippine Airlines experience.
I am not sure in the case of DPS to OZ flights and vice versa but KUL and OZ flights thankfully use the same terminal. Even that being said, it isn't an experience to relish.
I have transited several times through MNL and the whole experience is very hit and miss. You follow the signs for immigration and flight connections. There you find a Philippine Airlines transfer counter. PR generally issue all your boarding passes at origin point so if you are in possession of your onward boarding pass you can proceed direct to transit security where you will either pass straight through and up some stairs and be back in departures - or - be told to wait for anything up to 45 minutes before being allowed to head up. Why the wait? Well, when you do go up the stairs and emerge in departures if you turn around and look at the door you've just come out from, it isn't just the transit corridor - it also doubles as a bus/remote stand departure gate. So, if PR is boarding a flight from that gate at around the same time you need to use the transit corridor up to departures you will have to wait until the flight is boarded.
This is all outside of PR's control unfortunately. What IS in their control however is their 'flagship' lounge at their hub. Disappointing is the word. It is small, outdated, dark. To be fair the food options are quite decent, they had some nice slow cooked fillet of beef in there last time I transited. But the entire place is like something out of 1997.
That being said, the KUL transit time is pretty decent, the DPS I would likely avoid - unless you leave the airport for a meal or such altogether.