I guess Mike will have to answer whether it can be done, but as far as my answer goes, I read in one of you posts that you use a ball mouse, and so do I.
I got used to it many years ago, and love it.
"They say" (whoever they are) that the ball mouse is not as easy to accurately drag a box or a lasso an area.
I don't have that complaint as I guess I have mastered the ball mouse.
When I am trying to crop to a certain dimension, Qimage is reading out pixel count in one pixel increments. It makes me concentrate a little harder to find that last pixel number, but it is rare that I need to copy someone else's crop dimension to the exact pixel.

Not sure what your aim is, but I will mention that you have a CROP WIZARD button that will set the aspect ratio for standard crop sizes, and you can type into the teo boxes the crop ratio (sizes) that you want to use and tick Crop Lock.

Even if you know all about these features, I mention them in case someone else can use the tip.

Fred