I would need to know more about the question before rendering an opinion---In other words, if you are asking how much vertical material is available before the seat ring is gone, the answer is about a quarter of an inch. If you are asking the vertical distance downward until the block eyebrow needs attention that will depend on the initial status of the seat.
It usually requires less than .030 to solve even the more serious problems. .060 would be a rather extreme problem seat.