I'm not sure if it's emulated yet, but you can always try to enter in more controllers in the plugins configuring menu(DC can have up 4 controllers meaning 4 mem cards). That's logic, but if it doesn't work, you can just keep making a copy of the VMS save file(when it's not full of data). This way you keep all of the full mem cards in a different folder and just replace the one in the chankast folder with a new memory card whenever you need to use that particular card. It's not that hard actually...