Wow!
Hi witsendafter10
Thank you for sharing your question here.
I want to join
Tattered Heart with supporting you with a congratulations on your wife agreeing to residential treatment. For partners here, sometimes even working toward the symptoms one by one is so difficult.
We are going to start working on DBT together ... .
Wonderful. I've heard DBT is so useful. Having looked at some of the techniques myself, I think there can only be tremendous value for a pwBPD using them.
... ."Stop Walking on Egg Shells".
This is so good. A P that I consulted with recommended this to me. I read it too and found it fabulously helpful.
I have some loosely set boundaries (ie, when she starts yelling or screaming that I will leave the room and wait until she calms to continue the conversation)
I think this is an excellent boundary example. Even if you describe it as loosely set, that you've managed to make it work--I want to hold out props to you and your wife. The benefit from this boundary is that it will encourage respectful communication for you to handle for when she triggers into yelling. At the time, I didn't have this boundary when I was working with my SO, and communication was extremely hard for me.
I wish you peace and a fruitful time with your wife through the treatment.

While parties are a mother and a 13yo daughter (pwBPD), this
journal might be useful with adding to a general understanding of how DBT treatment might work. While a parent-daughter relationship is clearly distinguished from an intimate partner relationship, I do think a lot of the skills apply to both; e.g., distress tolerance and emotional regulation.