Right now, if a post is edited 10 times by its author, it will be automatically converted to CW (Source). I think that this is flawed logic, and should be removed.
I'd argue that having the auto-cw feature is a deterrent to authors maintaining high quality posts. Without the edit limit, authors are have a dis-incentive to updating their posts. So you wind up in a situation where posts go out of date (and can be -1ed) because the original author didn't want to lose ownership (and rep) associated with the post.
This answer was auto-converted to CW because the poster expanded the body a few (ok, 9) times with additional examples, references and more information. Does that make it a clear candidate for CW? I'd argue no.
This answer was not auto-converted yet. But I'm discouraged from editing more unless I really need to since I don't want to have it auto-convert...
We already have the mode where if a post is edited by 5 users it automatically becomes CW (which makes sense). Why not just leave it as that. Let the users say if it should be CW by actually contributing to the post, rather than just saying it should be because the author took the time to expand the post.