The position of the labels can be adjusted, it's just that its super fiddly. Getting you cursor on the the control point is a little easier if you first drag the corner of the display box to make it bigger. One of the developers probably knows the exact location, but it looks like the pixel in the middle of the first or second number (middle, top to bottom) is about where to click. It takes me 4 or 5 try to get it most times, but its definitely there. I'm pretty sure its the same in older versions, but I know for sure that it works in v16.
JMP Systems Engineer, Health and Life Sciences (Pharma)