ROM Hack Question Switch game duplicates rumor from last year

[unvaluablespace]

I remember reading last year that supposedly Nintendo could detect if a duplicate copy of a game is on their network twice, and could potentially ban both systems. It even sparked a debate about buying used games from places like gamestop. Whatever happened with that? was it true?

I'd like to make a copy of my physical cartridges from my legit switch, to use on my hacked switch. I'm afraid of the potential risks though.