Now it seems clear that the BMW Australia response is based on their SB that if the B series engines do not have GPF, note 1 applies so that LL04, LL12FE and LL17FE+ should not be used outside EU .The B-series was always approved for LL01/LL04 down to LL17fe. Choices were made based on local markets and fuels.
In the US BMW has been using LL01fe or LL17fe for B-series engines since 2018 or so. The US moved to ULSG in 2020.
IIRC Australia is going ULSG at end of 2024.
I double checked my B48 engine, couldn't find the SA1DEA RDE option in the VIN decode reading. I neither could find the vacuum hose on the catalytic converter. Apparently, for B48, the GPF is integrated together with the catalytic converter, differentiated by having or not a vacuum hose and part numbers.