What would be the result of the psych eval -- legally? That is, what would the results have to be for the courts to grant you full custody from the mother? (or is that what you're after?)
Well, assuming she is diagnosed officially with BPD my therapist told me that is a pretty big deal. Courts are supposed to look after the "best interests of the child" and while fathers don't normally get custody in my state (I already have once before) I've got a long track record and can stand toe to toe with her even without the mental eval. With the eval, BPD is a serious disorder where she can just cut off her feelings for anyone - including children - and it would be an emotionally abusive upbringing, and would possibly lead my daughter to develop similar problems due to environmental factors.
So I'd make a strong argument, and hope we get a good solid case behind that. If we get an expert opinion that says this would hurt the child - it will be hard for them to white wash it.
"You can't reason someone out of a position they didn't reason themselves into."