An example is with a layout having multiple objects placed horizontally.
The top coordinate of all the objects can be different, but they must line up at the bottom.
I can’t think of a better way than to select them all and then type the bottom coordinate in the Inspector field labeled “Bottom”. Entering the bottom coordinate changes the height of each object while leaving the tops in place. It’s effectively getting the computer to do the work of recalculating the heights so the bottoms will match.
Stretching, the original subject of this post, is for that case where the group needs to be made taller or shorter by a pixel, for instance. A Command-Key plus down-arrow-key would be a fast way to get that done. Also, since I always get it wrong a few times, keystrokes are much more convenient than returning to the field and retyping the number.