This sounds like a load of old balls if you ask me they are scare mongering you...
If the po po in Oz have time to randomly pull over cyclists who have not yet committed any apparent crime to check if their pushbikes are legal then all I can think is you lot are pretty well behaved in oz and the po po have nothing better to do
For me the cops would have to catch me first that's assuming I was worried enough and also hadn't turned my handle bar mounted throttle limiter down anyway (yes its current limiting too) OK if i were in an accident and were not able to turn it down then I would be in trouble but that's assuming I didn't hurt anyone but me.
We have very restrictive laws on power over the here pretty much the same as in OZ, I simply would never ever ride an ebike if it were crippled to 250W, in over 12 years of riding them I have never ever been questioned by the cops about it not once, if you are sensible and do all the right things you wont have a problem, this includes having lights on, having working brakes, not riding like a maniac, being courteous to other road uses and ride in a safe manner, you can do all this with 2KW on tap and even though your power is not legal you are on paper much safer than none assisted cyclists as you are more likely to be able to stay with the flow of the traffic, get away from stops quickly, you wont be weaving right and left whilst climbing a hill etc etc.
Wouldnt it be much better for the cops to target proper asshole cyclists like the ones that ride the wrong way up the road, with no lights, the ones that jump red lights, the ones with no brakes like most BMXers (who also almost always ride on the sidewalk too)
Its very hard to prosecute based upon dyno evidence too as most of the off the shelf so called legal kits will exceed their specified limits under loading anyway, if this is true? its a prime example of yet another knee jerk draconian ill conceived plan to thwart peoples attempts at cheap and friendly low tax transportation, its nothing to do with safety and all about making money.
If I were in OZ I would do as the Jester and Hyena do and just ride and enjoy