Hahaha.. .like you’ll have time to worry about the metal fatiguing... good one.
That timing belt (chains are less efficient and less smooth.. fuel economy you know) in that interference engine (since fuel economy is tops, non interference will go the way of the buggy whip for that extra 1-2 inches of compression) is going to snap and kill your engine long long long before the metal parts die from fatigue.
I always liked the sound of an aftermarket gear system that replaces the timing chains, man those things sound nice when they got up to speed...