the ‘open vase’ pruning like that is good for air and sunlight getting to fruit. that definitely helps in fungus-problem-prone trees like nectarines. if that pruning made the difference between getting much more of my crop and not, i’d probably do it.
in nectarines, more red blush like you get on the sun-kissed parts probably improves their marketability, too.
there is always a bigger fish to eat the tiny ads: