Hi DRP and Welcome to bpdfamily.
Sounds like you have some type of custody agreement in place and at issue now is your xw's escalating behavior with DV allegations and failing to adhere to the communication protocol for the children. Is that correct? Can you elaborate a bit more on if you have a documented court order/parent plan and how she is failing to meet the requirements of that plan?
Regarding the false DV claims, have you documented the frequency and result of each one that the police have been involved in? It would seem worthwhile to bring it up again, but perhaps as a written record of evidence. However, from the experience on this board, family courts tend to focus on parenting behavior v. personal behavior. The judge may construe this as sniping between you and your ex. Try to portray it in the light of how it is harmful to the children. Are your children receiving therapy right now? Given the chaos of the situation between their parents, it might be a good thing for them. Again, proposing things like therapy for the children is seen as problem solving parental behavior, which the courts typically see favorably.
Keep communications limited to written v. verbal, as much as possible and keep to BIFF (Brief, Informative, Friendly, Firm),
https://bpdfamily.com/message_board/index.php?topic=133835.0. Keep pick ups and drop offs at neutral sites (school, grocery store lot, church) to extent possible. Depending on your state laws, you may choose to record when you do interact with your xw.
Regarding boundaries, I was advised here that boundaries are neither abusive nor cruel. I think that's a hard one for most of us on these forums. My hunch is that pwBPD are attracted to people with weak boundaries, and people with weak boundaries are often co-dependent and attracted to pwBPD. All this to say, many of us on the forum have trouble differentiating boundaries as healthy v. abuse. Your boundaries don't have to invalidate your xw, but they are a part of what you value and hold as important in yourself, and as such, they are worth defending and definitely not abusive. If anything, it is a cruelty to not have boundaries (consistent, clear boundaries) with pwBPD, as they are always desperately seeking them to fill in the picture of who they are.
Others will weigh in here with a lot more experience than me. Keep posting and let us know how the settlement goes.