> The Australia law caused a bunch of trouble in the last 10 years

It has, although the case you mention isn't really my main worry.

In theory some random rogue state (Hello North Korea!), can just grant all of the Australian parliament citizenship. Suddenly they're all ineligible under the constitution.

That said, I assume modern scholars would make the definition more robust than the 19th C definitions used in Australia (which was an attempt to take the best of the UK and USA models, particularly following the US with regards to being a Federation of States, while still maintaining a proper Westminster system without a "King"/Executive branch like in the USA).