Animation curve is not preserved after unparenting a layer

With separated dimensions, easing is fundamentally flawed if a layer has been unparented:

1. Imagine a shape moving left to right + some easing applied (with separated x and y positions)
2. Then it is parented to a comp-centered Null that is turned 180 degrees.
3. The shape now moves right to left. 
4. Either delete the Null or unparent the object from the Null.
5. Values change accordingly (the object still moves right to left), but the easing is still the same – it has not been transformed to comp-space.
   
   That is especially apparent when one used something like an ease-in or ease-out curve that starts/end abruptly (curve starting/ending in non-zero pixels/second).