This is not entirely what you want, but if you build the corner radius into an applied object style it's pretty easy to remove the override from scaling and reset. Could probably even be scripted to look for all objects withteh style applied and remove overrides so you'd only need to do it once at the end.
Thanks for the reply and acknowledging my post. The object styles is slightly easier than inputting the value each time you scale. Was hoping needs for a hotkey or setting simialr to "Adjust Stroke Weight When Scaling".
Can't believe that there is not more response to this post, as this is such a common need, and InDesign is not a new product. Please chime in to this post if even to say this needs to be fixed.
Thanks for your reply and desire to help. I realize that but found that you can only adjust width or height and not even scale to get this to work,and other problems with this method.
I am only interested in being able to scale both frame and image simulataneously and holding the corner shape.
For a program called InDesign, the lack of this essential basic feature is NOT DESIGN friendly. Anyone designing a catalog would be wise to avoid using anything else but square corners on images.