M - I think you know you have arrived when you can talk and interact with your W BAU with no emotions, no expectations, etc. just like you would interact with anyone that you come into contact with.
When I talk to my EW these days it is just normal BAU behavior. I respond to her texts, emails and I don't feel any pressure to wait like 3 hours or not respond at all if it is just informational. I might just say Thanks! but it isn't in some attempt to win her back. It's just normal convo.