There wasn't any way to disable it back then that we could find, and I was told that authoring with tags on like this may not be that common. I do it all the time, but I digress.
I can tell you that, at least in my experience, that box pops up only when your mouse cursor is over an element tag. So if you get in the habit of moving your mouse away from the elements after you click to select them, and then press CTRL, you won't see this popup. So, there's a workaround.