The Indonesia comment was a bit of cheek, I totally concede that it would be disastrous for them. However, I don't think that a conventional invasion is too far fetched IFF USN assets withdraw from the western Pacific.

Yes China has to transit the straits around SEA, but how many Collins does Australia actually currently have available to deny these channels, 1 or 2? Additionally, if this scenario happened and the US was in full turtle-mode, how long do you think AU could sustain those F35s? AUKUS won't deliver actual capability to Australia until maybe 2035 at the earliest, and those subs are too large to feasibly use the channels around Indonesia and Malaysia effectively anyway.

But yes I agree, unconventional attacks are more likely.