Thanks again for the 5V test, Cathar. The low airflow performance is most impressive.
However, your noise estimates look a bit optimistic.
YL rates the low-speed D12s at 24 & 28 dBA, depending on bearing. The sleeve bearing is the louder, which seems odd; perhaps they swapped things. In addition, MikeC at SPCR
measured the Nexus at 22-23, and that's a 25% slower fan.