Bad news. My resolution is 1366x768. In case it helps at all, I just checked again to see if there's anything else to gleam from the issue. The area the in-game cursor covers is in the top left, so only the bottom and right of the screen are out of reach. As such, I was able to take a screenshot with the cursor as far from there as possible and find that the size of the in-game cursor's range is either 1121x574 or 1122x574, depending on which pixel is the actual anchor. In addition, if the taskbar is told to go away, it adjusts the range by a couple pixels more in both directions. I also found out that if I move the game window at all, the limited range goes away completely, but at the cost that the game is no longer scaling down at all, nor does it fit in the window.