I agree with your thoughts on being misleading. Would you believe it’s taken me a couple of years to finally get a grasp on how best to use control points effectively? See my post here
In fact, as powerful as the control point tool is, it’s phenomenal capabilities are very inadequately covered in the manual and other tutorials.
The impression you get from what is out there is that it just needs one (maybe a couple) point to cover an area, surrounded by loads of negative points to constrain the effect.
In my recent experience, it can actually take several points to include differing tonalities in a desired area, otherwise parts of the area that differ in tonality do not get effectively selected.
So, in addition to raising the subject of changing the shape of the affected area, might I also raise the subject of better documentation of what it does so far?