@klonoa02, Not sure if that will hurt your Nand or not, not wise to use fake SD cards, or not check them beforehand with app like H2testw. I'd let it finish personally, or attempt to.
If you have a Nand backup then I'd say go ahead n stop it, or power off the switch, at worse you can rewrite your backup Nand back if it messed anything up.
Ugh 3 external hard drives, 1 works fine 340GBs or so lol an 8TB external not working an external 2TB drive that kind of works, the Wii can see the games but no loading lol