If you haven't hacked your switch yet but would love to do so, make sure to setup emuNAND for hacks and sysNAND should be kept for your online needs.
A NAND backup should be made beforehand.
If online play is all you want and don't like to hack it just update your system and go the legit way.
on a last note, emuNAND should be kept offline at all times.