I finally managed to boot freedombox on my RockPro64 
I also have the NAS case and would like to setup 2 HDDs with it.
However, the NAS Case wiki page says
the SATA adapter from PINE64 store is low-quality and will not function well with two SATA HDD
Is anyone running freedombox successfully on RockPro64 with 2 SATA HDDs? If so, which SATA PCIe adapter and which PSU are you using?