The other issue is does the CoA or the RAN want to keep on using major fleet units to back up PBs where their endurance and sea keeping are found wanting? An ANZAC or worse and FFG or in future an AWD cost exponentially more to use in BPC support than an appropriately sized OPV would.
Back in the early 2000s everything was being thrown at the problem, Freos, ANZACs, FFGs, MCMVs, survey vessels and amphibs. Helos were on board these ships, Seahawks, Sea Kings and Squirrels. It was serious issue that needed a serious solution. The lesson I could see in the situation was, had the corvette procurement gone ahead as planned in the late 90s the RAN would have had an appropriate deign entering service to handle the problem, smaller and cheaper to procure and operate than a frigate, more capable than a PB. What did we do instead of going back to a corvette or OPV, buy a larger prettier patrol boat. What are we doing now our larger prettier patrol boats have been found wanting?