Reported today - a US Admiral says SSNs for Australia would disrupt US and UK production lines.
While in the same report the UK Defence Secretary Wallace goes the opposite way in theorising the US and UK might restructure their production methods to meet Australian needs, ie:
“Australia's submarine "may look like something none of us have in our stocks", with the latest post-Astute class submarine designs fully shared among Australia, Britain and the US.”
There appears to be considerable miscommunication between the US and UK already on the implications of AUKUS.
International alliances to build completely common SSN types been never existed. One reason is the US would impose the extra high cost of the US administered SUBSAFE program on the UK.
What could go wrong with Adelaide possibly designing, but more definitely building, an unprecedented common-hybrid submarine? This would combine UK features and US features, with the latter requiring the US SUBSAFE Program be applied to Australia. As one of the costs I understand SUBSAFE requires all submarine commanders and executive officers having nuclear engineering degrees before they can command a nuclear sub.