The problem:
I’ll be working in one file where I turn snap to pixel grid off because I’m working with type or vectors or really small distances and then I’ll move to another file and forget that snap to pixel grid is off so I’ll resize things and they’ll end up being off by like .02 pixels.
Solution
Make snap to pixel grid setting only apply to the file you’re in.
(Oh and it would also be awesome to have a snap to pixel grid setting that is just for smaller amounts so it snaps to .25 and .5 pixels but that’s something else entirely)