J
@VectorStyler
I think it would be most useful when multiple objects are selected. For example, if you have a circle in the upper left and another in the lower right, if you just have the bounding box highlighted, you really just know that two objects in either upper left/lower right or upper right/lower left are selected. If you add 3 squares in the middle of the bounding box, there's no way of knowing if all three or, if any, have been selected.
The handles of the objects, even within a group, are no less important than they would be if they weren't part of a group. I just tried it, snap to point will snap to them, even if they aren't highlighted. Illustrator highlights them all and that's how I know an object is part of the group. You may be able find some way of intuitively showing that these objects are also selected. I always guessed that you just iterated over the handles in an object and highlighted them. Highlighting the handles within a group would mean iterating over all objects in the group. But, I may be way off with that-never thought about how to do it.
They behave the same way as the handles in a single object, so I would expect that highlighting them the same way would support that interpretation.
If I select a group and do a scaling or some other transform, I usually expect that the same transformtion would be applied to every object in the group with the same center of transformation.
I have never wanted to transform each of the objects in a group. Like having a set of stars that are in a group. To scale them all to 1/2 their original size is just not something I've ever needed. Unless I need to reset text to its original size-I select all the text and change the font size in that case.