Blancco Drive Eraser Evaluation version is not capable of erasing special special disk areas, such DCOs, HPAs and remapped sectors (more information about the special areas, see the Blancco 5 user manual). If the software detects these special areas during the erasure, it will report if they are not erased. "Erased" result (without any additional notifications) means that the drive has been completely erased (i.e. no problems with the overwriting process and no special hidden disk areas detected).
Blancco Drive Eraser cannot be used for erasing systems with RAID. Blancco Drive Eraser Evaluation version is based on the Blancco Drive Eraser "PC" version and it does not have any RAID dismantling or simultaneous erasure (i.e. erasing multiple hard drives/SSDs simultaneously) capabilities.