list of ban risks
• Piracy of any sort
• Homebrew nsps
• Changing user icon through homebrew
• Sketchy eShop behavior
Not so instant ban, but still a ban:
• Modding online games
• Cheating in online games
• Clearing error logs after they've been uploaded to Nintendo
Not a ban, so far:
• Custom themes
• Mods/cheating in offline games
(this assumes that you disable online syncing for games you intend to save edit of course)
Thank you to Val (Free Hugs) at ReSwitched server for this list.
My own experiment
I bought too many switches myself from ebay lol
back in June 28th 2019, I bought Super Mario Maker 2 game cart.
I put it in my atmosphere switch setup with emunand with 6.2 sysnand.
I created new account and linked it on this switch right in atmosphere CFW.
I kept updating it normal via Nintendo servers in emunand. I also do game updates normally in atmosphere CFW.
It gone thru 3 updates now. I am still playing Super Mario Maker 2.
I admit that I did injected my saves from my banned unit to this switch.
I also using my own custom themes and fonts on this switch.
only thing different is No Sigpatches and GoldLeaf on it.
I only use game carts and my purchased eshop games.
This shows that any kind of piracy will get your switch banned.