Your realism and your determination are more good things.
I guess you can't control or manage how the therapist might handle any potential diagnoses, but I wonder if you have a sense yet of how diplomatic he might be if he has to communicate difficult findings.
I think he will be very diplomatic... .and he realizes that figuring out the issue or issues with uBPDw is critical to getting a functioning family unit back again.
He's also been direct with me about saying that he is confident he can figure it out (the dx)... .but also has been putting the notion in my head that I need to be prepared to be "the healthy one" and that there may not be a miraculous recovery by my wife... .or that it may take a while.
He knows about BPD... .and is prepping me that is may turn out to be more PPD (paranoid personality disorder) that BPD.
So... .the good news is that I feel I'm in good hands and that the pattern has been broken.