The best advice everyone is giving homebrewed users right now is to simply stay off the grid (as in, have their Switch offline).They'd actually ban people for hacking their device locally? I mean you'd have to try to snatch a digital title (a la freeshop on 3DS) to earn a ban no?
We don't know what data Nintendo is getting and what they're actively looking for.
To my knowledge, we also don't really know what's causing those bans yet...