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.