EDIT: at first I suggested making it easier to deselect stockpiles. However, I have come to believe it much better to make it harder to select them in the first place (see my second post in this topic). That’s why the title and the rest of this first post don’t seem to match as well.
It’s quite easy to accidentally click on a stockpile when you attempt to select an item in it (see the video, e.g., 43:04 (the error messages are unrelated—also, it doesn’t seem that bad there, but I was used to it by then; I think somewhere in the video is a better example, but I missed it going through it once and did not spot it going through it again at 3-4x speed and I can’t be bothered to do any more)). I think it would be good to be able to easily deselect it as well just by clicking on the ground next to it, rather than having to click the X button to exit the Zone Tools mode. I can understand that you would want to stay in this mode if you explicitly opened it in the toolbar at the bottom even when clicking next to a stockpile, but it’s slightly annoying if you just accidentally clicked a stockpile. Not sure how to compromise there, I’m just reporting my findings.