Let me give a scenario:
Say you have a character that walks and stops in place, and then the character bends down (feet stay planted) or something like that.
Right now to keep the feet planted, you would toggle on the transform limit for the feet to keep them stationary, and this would cause the feet to reset to default position making them move elsewhere.
To fix it, you now have to move your feet back to the frame where they were a second ago and rescale/skew/whatever to have them be the same size as before you turned on the transform limit.
If we have a freeze transform limit node, it would allow you to 'freeze" the exact position/scale/skew/whatever, and then once transform limit is turned on letting you move legs/body around without having to manually reposition the feet to be the same as previous frame.