If your emuNAND is already formatted for use with Gateway, then all that is needed to make a backup of your emuNAND first before you install the system update + patches.
I highly recommend that you update Luma3DS and your system first.
Wait, so I have to update my SYSNAND??
I wasn't in the 3ds scene since the last GW update (that's 8 years ago) , and back then it was a big nono to update only the emuNAND so I'm a little hesitant on that regard.
So is it really safe to update...
without pubg popping off, fortnite wouldn't add battle royale, and call of duty wouldn't go even shittier than it did before because of blackout, warzone and dmz