My T mentions integration often but he always adds that it is up to the parts if they want to integrate or not. He always says we can never get rid of one another. Even if some do decide to integrate he says it is like breaking a glass window. You sweep up all the pieces melt them down and make a new pane of glass so nothing and no one is ever lost.

He emphasizes that integration usually happens (if it does at all) after certain parts start to heal and their old role is no longer needed. Like two helper parts might decide to combine or a couple littles might decide to combine especially if one or two decides to age and gets close with another little.

Every system is different and you can't force anything on anyone. That is why my T only pushes for more communication in the hopes of building cooperation at this point. It is a long process and some might decide to never integrate but increased cooperation can still make your life a lot easier and less traumatic.