I recently discovered a very useful feature in the Elements ACR dialog. I only used the crop tool freely as an excellent non-destructive function. What I had not found is that you can open a drop-down menu to select various aspect ratios or to remove the previous crop definitions: - press the crop icon for several seconds:
You can even define your own custom ratio, for instance 14,14 to 10 for A4 paper, which is very near 5:7 - (14 to 10) Your last custom ratio is remembered next time. You can apply the same ratio to several selected images in the ACR dialog.