The link-constraint is hard to control in an animation and the animation of a linkconstrained object is easy to break if you change the setup of the involved nodes. For example - you have a character that gives a pen to another character, where the pen is driven by a linkConstraint. Now you (have to) change the animation of those characters and change their positions. Due to this change the pen-animation is broken and it has an offset to the characters hands that needs to be fixed manually.
The IDEA is to have a 'Follow-Constraint'! Instead of settings nodes to be linked to at a specific frame in the linked-constraint, you would define frameranges and nodes to follow. By follow I mean a 1:1 match of the transform-values (PRS) and this would avoid manual fixing like descriped above. Getting back to the animation-example you would just add two hand-nodes of the characters to the 'Follow-Constraint' of the pen and define the frameranges where the pen needs to follow which hand.
