I love the ability to toggle a tween position.
I do not love the way it jumps to and from the "to" and "from" positions when you toggle it in the middle.
I made an inelegant solution to this, but would love to see a built in option that uses the current position as the "from" for the given move (not the same as the "from" field, obviously, since sometimes you're moving to the "from" field.)