It’s a live ball until it goes out of the field of play.
Exactly.
There was a thread last week that you might have seen wherein some freepers were suggesting that it can’t be a TD (or shouldnt be) if only the ball breaks the plane. That it should only be TD if the runner gets some part of his body into the end zone.
Just a fundamental misunderstanding of your very clear statement (oh and the rules of the game) - It’s a live ball until it goes out of the field of play.