Thinking about building NAS power by POE++ (60W max) like UNAS but getting 4 bays seems impossible because of the HDD power usage.
I guess that's why Unify use POE+++ (90w) instead of POE++ for 4 bays (they have POE++ for 2 bays)
Alternatively, 4 bays NVMe drive but the storage density is not there (like 20TB+ drive, no NVMe has those range yet, maximum 4TB)