From c4evaspeaks.com:

Work on this drive is temporarily suspended while v3.0 is in progress for other drive models.

The original fw of the DG-16D5S 1175 drive has been dumped, but employs a new encryption that is different from the older DG-16D4S drive model. There will be no further progress on cfw for this drive until the encryption algorithm is reversed and the ofw decrypted.