Re: 22 hours feels like a bit of an endurance test
I did the 3 day stopover in SG the last time I went in that direction, and there's plenty to do, see, and most importantly eat.
Never been to Dubai (apart from the airport) and have no plans to.
IMO, and based on experience, having a couple of days somewhere in the area (KL, Hong Kong etc.) saves you from crippling jet lag when you get to AU or NZ.