If you mount it to the Plex, you could also share it out via samba. I know you can also mount shared drives, so if you had it shared as a samba share on one container, you could turn mount that share as a folder in the Plex container. I would have to ask more expert people than I am on how, but I know you can mount a share as a folder in a Linux box, so I assume a container would work the same.