It’s probably worth acknowledging that there’s a big knowledge gap here. This flavor of Switch homebrew is so new that it’s not as if there’s any kind of sophisticated analysis into the security features of the console as of yet. We don’t know what detection methods Nintendo has in place concerning repeat certificates. It would have to be lenient enough to allow selling cartridges and letting friends borrow them, so if there was such a barrier in place, it would most likely involve trying to detect multiple instances of the same certificate running at once.
However, there’s reason to believe that, with the right care being taken, there’s nothing to worry about. YouTuber J.P. of Alien Retro Gaming discovered in mid-January that you can rename any certificate to match a different game and it will work. In theory, this means that you could mix and match the certificate of a cartridge you own with internet-sourced ROMs and avoid detection. But we don’t know that. J.P. also added that while online play technically works with the MIG-Switch right now, there’s no reason to think Nintendo won’t find a way to change that before long, like being able to detect mismatched certificates.
