Is It Possible to Retarget Mecanim Transitions?

Let’s say I have a State A with transition T to State B, which I’ll denote as A-[T]->B. If, instead, I wanted to transition from A to C using T, (i.e. A-[T]->C), is it possible to re-target T from B to C? I’ve tried clicking around on endpoints of T, but can’t seem to “pick it up” to move it around.

Ultimately this is a workflow issue as if you ever need to change a State (or animation), or perhaps insert a new state between two others, you have to completely re-wire all of the transitions associated with it.

No, there is no functionality to copy or retarget a transition in mecanim. It is possible to achieve that functionality through custom editor scripts using the UnityEditorInternal namespace, although it is undocumented (and therefore unsupported).