Interesting but flawed.
Reading this type of analysis always reminds me of the course I did in Uni on" Political Geography - boundaries & frontiers" where the Prof, wryly used to point out that no country ever decided their best boundary was closer rather than further away and it should always be on someone else's (current) territory.
The "strategy " laid out here is totally Australian -centric and has several elephant traps buried in the basic assumptions:-
The goals of forward defence in depth are to prevent a major-power adversary from threatening Australian and allied forces and facilities across northern Australia unmolested; to deny them access to our air and maritime approaches by controlling maritime straits across Southeast Asia; and to ensure the ADF can respond rapidly to coercive threats to our energy and maritime trade on the high seas.
Sounds very much motherhood & apple pie until you start to think....... point one - fair enough, point two "controlling maritime straits across Southeast Asia" ignores the fact that these straights are both in other people's countries AND are vitally important to many countries - especially China. ASPI see this as "defence" - China would see it a " trying to strangle our maritime trade" - similarly with point 3 - it's clearly aimed at operations well away from Continental Australia. The defence chain advocated runs Okinawa - Guam - Lombrun - that's 5000 km and it runs NW-Se - it protects the C Pacific & Hawaii but doesn't cover Australia - Lombrun is EAST of Melbourne for example. A far better line would be Bali - Timor - Moresby - Honiara
There seems to be no recognition that any serious "attack" on Australia proper would have to come via SE Asia, Philippines, Indonesia and/or PNG - whilst none of these has a serious military force I can't see the Chinese trying to fight their way through 250 million Indonesians to get to Broome (especially given the warm feelings most Indonesians have to people of Chinese origin....) and imagine trying to cross PNG......
The dangers of a forward policy are that you get into the trap like the British in India - always pushing forward, always having to meddle - and finishing up in Kabul without a way out.....
Australia would be better to think of the Russian model - trade space for time - and Vietnam/ Afghanistan - get the buggers trapped fighting in SE Asia - so training for other countries forces, development of shared values, and maybe some suitable low(-er) tech kit