For all you are asking the answer is "Hekate"!
Hekate, more exactly NYX, allows you to restore any sysnand backup, check for burnt fuses and a lot of more things.
If you did use EmuNAND from the start and never boot on your OFW you don't need to restore it, only use your backup to create a new emunand and start over on it. if you did modify your sysnand and never go online is safe to restore you sysnand. but if you go online with your sysnand on any point, restore it and going online after that is a ban for sure.
be sure of read
https://nh-server.github.io/switch-guide/ for more information.