I still haven't seen this answered. If hold the menu+down button for 5 seconds to force a reboot of the Apple TV, does that mean I would have to connect it to my Mac again because of the untethered jailbreak? It's not a full power down so I'm not clear on it. Certainly somebody must know.
AppleTV reboot will kill the jailbreak. You can do a reboot of lowtide, without having to do the jailbreak again.