From the article it's not clear entirely how you'd set about to clear your name / title if you were on the receiving end of a fine issued on the basis of a fake plate. Similarly not clear whether drivers could claim fake plates to get out of legit traffic citations.
If you can use ANPR evidence to show a plate being in two places at once, that should be sufficient. A parking garage might have plate records too. Even something like roof racks or stickers on a vehicle might be enough to distinguish it.
I guess if you were a municipality you might respond by increasing the frequency and coverage of ANPR and imtegrate alike systems, like you suggest garage records and location tracking, to compensate. TPMS has been used in traffic flow management, and a lot of places have transponders for tolling or private access.
Increasing surveillance might be controversial but maybe less so in .au?
License plates do seem anachronistic, ANPR notwithstanding.
Depending on the sophistication of the operation it opens up some interesting angles - if you can pay a gig worker to wait in line or chauffeur you, seems like it wouldn't be much more to pay someone to put on a plate and drive around safely. A /get out of tickets/ service.