I'd love this feature personally. I use many image points on a variety of sprites for armor skins and weapon animations, over many characters.
Sometimes I need to quickly see if one image point is off compared to another, or to compare multiple image points on different animations (this is particularly tedious). Other times I need to see if I've forgotten to set an image point, and have to click through them all to find the culprit (again, tedious at the scale of animations in this project).
I think a tickbox option in the toolbar to show all, that stays enabled/disabled as you click different animations, would be really helpful.
Or even have them all always visible when in the image point tool, and move them as you like. Selecting an image point from the list would hide/dim the others.