I have been using emunand since release. I don’t create any host files, dns etc. Because people forget if you take the switch with you to a different location. All your settings aren’t in place.
anyways, when I got my switch up the very first time. I just set up my switch like normal. Connect to WIFI, sign in and link your NNID etc. When on Home Screen, remove your WiFi settings. Put in to aeroplane mode. Ensure all other features are on for Jon cons etc, that’s it. Don’t run any games etc make sure no game card inserted. This will be your cleanest nand dump. Use the most recommended tool to take a sysnand dump. Do it three times. Then to a comparison. If they match done. You can then go back and enable WiFi on the switch on sysnand. With your nand dumps you can use these for your emunand. Set up emunand. Update to X firmware. Then back it up to a safe location, gdrive, NAS etc. I have all nand dumps with X firmware going from 4.1.0 up to 12.0. Reason for this, if something happens with your emunand after installing anything, your sd card dies. No worries just grab your latest emunand backup from your gdrive, nas etc and copy back over. Done.
some other things I do just to ensure I’m on sysnand / emunand. I use one micro sd for sysnand 256gb and a separate micro sd for emunand 512gb. I also have the black background for sysnand and white for emunand. This method I’ve been using with SXOS since launch and I have recently switched to Atmosphere, no issue. No ban risk.
I hope this helps.