Hopefully this is really straightforward and my brain is just not working today.
I have some encrypted USBs (Biometric) that have been in use for a couple of years, haven't had to do anything with them for a while. Until today, when a user managed to lock one of them. It was at that point I realised that last time this happened I used a recovery option in the ePO console.
And therein lies the issue. Having upgraded the console recently I can't find where the Encrypted USB management options are or indeed how to add them back in (if that is even possible in ePO 5.1.1)