Hi Folks,
From some googling I think this isn't possible but it'll impact how I architect things.
Unraid booting from USB
Pool of spinning rust
SSD partitioned in half, one passed through to a windows VM the other mounted in Unraid for a plex metadata store
If I can't then moving Plex from Unraid into the Windows guest will work but is probably slightly less performant.
Cheers,
Lemon.