Hardware encryption on tape drives?

Does anyone have experience with setting the hardware encryption key on LTO-4/5 drives?

I've been tasked with setting up hardware encryption on a Tandburg Data LTO-5 HH SAS tape drive for simple backups using xfsdump. According to the spec it "should" be as easy as sending it 256 AES-GCM key using SCSI commands.

I've tried setting my key on the drive using both stenc and setLTO4key but both of them return SCSI SPIN/SPOUT = 0x5.

My google-fu returns very little and I almost suspect that linux users aren't using hardware encryption on LTO-4/5 because it seems to be a serious PITA.