I'm fairly certain, without looking it up, that warning penalties don't carry over into a tiebreaker.
I was an official following a tiebreaker one time, in which one of the players had been warned and then penalized for footfautig during Round 4. He foot-faulted again on the first hole of the tiebreaker---but it wasn't called, and didn't matter, because he'd effectively lost at that point.
But the question arose in my mind, and I researched it or submitted a question, and was told that the tie-breaker was a new round. Of course, it may not have a 2-minute warning, starter horn, or minimum number of holes. But my understanding is that, generally speaking, it is considered a new round.
I was an official following a tiebreaker one time, in which one of the players had been warned and then penalized for footfautig during Round 4. He foot-faulted again on the first hole of the tiebreaker---but it wasn't called, and didn't matter, because he'd effectively lost at that point.
But the question arose in my mind, and I researched it or submitted a question, and was told that the tie-breaker was a new round. Of course, it may not have a 2-minute warning, starter horn, or minimum number of holes. But my understanding is that, generally speaking, it is considered a new round.