You don't need a flashcard to play borrowed 3DS games?
Found that on Google. There’s a way to run other region games on a different region 3DS. So you could buy non US games and play them. Don’t know if it still works though. I’d have to turn wifi back on to do it.
You’ll need to downgrade your firmware if you want to play games. You can backup your games and save files without downgrading the firmware.
If you go to the last page, it’s been patched.