If you vote outside your local area there is extra steps and you need to let them know. They usually ask everyone; “if you’re voting outside of area”, join this line.
Extra verification and proof is needed if outside of area. I think behind the scenes, the fact you voted out of area is communicated back to your area.
Voter fraud is very low in Australia. With compulsory voting of all ciztiens, the quantity of votes is very high. We have 98% of the population enrolled to vote fyi.
So with these quantities, the incentive of say double voting fraud is greatly reduced.
In spite it's not very useful, we had some double voting fraud by the observers of the political parties. They should vote in their designed polling station. But if they are observing another polling station they may insist on voting there (too). Everything is tracked on paper, so it's easy to discover, but some try anyway.
In Australia this number is statistically insignificant, so inconsequential.
Right wing commentators have attempted to mirror US talking points on “stolen elections” but the recent vote shows very clearly that Australians are not wanting the drama.