If you plan on using online play with a clean sysNAND, then you should use an offline emuNAND for all hackery.But doesn't the use of emuMMC minimize the risk of getting online banned when on sysnand? Or is it too late for me since I've run Atmosphere? I have never been online so I could hypothetically flash my clean nand and go forward with emuMMC?
If you don't plan on using online play, there's probably no real reason for you to use an emuNAND.