Thanks for the suggestion Joe, but I've tried secure erasing the drive but to no avail. As above from the hdparm output the ssd does not show any security parameters (frozen/locked/enabled/supported/etc), and replugging like you normally would for a frozen drive doesn't change this. Neither does setting the password, even though it appears to succeed the status doesn't show, nor does any logging report a success/fail.
I've also tried just straight up issuing the secure erase command (with passwords, even though it doesn't look like they set anyway, and without - eg NULL) and the commands just timeout as per the logs above.
