Yeah I try not to prune perfectly good leaves. I remove --
1) yellowed leaves that are weakened and are likely to start showing fungal issues
2) leaves that HAVE powdery mildew, especially ones that are overhanging fruits -- don't want it snowing spores on the fruit
3) wilted leaves killed by squash bugs and stinkbugs
4) leaf covered by hatching event squashbug and stinkbugs nymphs/juvies -- fold with bugs inside, drop and thoroughly stomp or grind into the ground.
5) leaves that are in some way in a wrong place and must be removed -- after serious consideration. Example would be leaf growing into the path where I can't help damaging or trampling on it.
What I try to do and need to do due to limited space and almost every day due to their rapid growth, is to REDIRECT vines so they are growing in the desired direction or area.