Some 2d animation software out there uses some kind of smart control to change sprites, a good example of it is "360 head control", but it extends to angle arms, torso etc.
I would need some fews (I know if all run in viewport it would to heavy the process) events run in viewport and access to "initial frame" and "initial animation" to change sprite and animation in real time through other sprite position etc.
Ashley Maybe not now but in future would you add that ?