Can you play online with a hacked Switch?

You can do anything you want. Should you? Depends, if you want to get banned or not.

If I wanted to play online, I’d use my not hacked sysNAND.

I don’t play my Switch period. I should probably turn it off, and remove it from the dock, but I’m lazy.

If you have a patched Switch, it’s best to buy another Switch. You could have a emuMMC without homebrew or anything. If it’s using SX OS, you might still get banned.

Unpatched switches are nice.