> Who owns it? The MonoBehaviour? The caller? The thing it captured three yields ago?

The monobehavior that invoked the routine owns it and is capable of cancelling it at typical lifecycle boundaries.

This is not a hill I would die on. There's a lot of other battles to fight when shipping a game.

And then you're bending over backwards and have made so much more busy work for yourself than you would have if you'd just done it the normal way, in which all your state would be explicitly visible and auditable in the editor.

The biggest reason for using Unity is its editor. Don't do things that make the editor useless, and are invisible to it.

The problem with coroutines is that they generate invisible errors you end up shipping and fighting long after you shipped your game, because they're so hard to track down and reproduce and diagnose.

Sure you can push out fixes and updates on Steam, but how about shipping games that don't crash mysteriously and unpredictably in the first place?