He won't get treated or get a diagnosis... .but the symptoms are very clear to me after reading the books.
This is essentially calling his bluff. Has anyone done this and has it worked?
He is an adult and he has a right to live his life his way, it is not uncommon for a person with deep issues to refuse to address them - Denial, Blaming and Blame Shifting. However, your reciprocal right is not to have to stay involved with him or his life.
Calling his bluff... .how about let's refer to it as "setting a boundary"? And of course people with an acting-out PD such as BPD don't like boundaries and try to trample them or have an 'extinction burst' trying to get you to retreat from your boundaries. If you feel this is a good boundary for you, then it sounds appropriate.
Short marriage and no children from the union? Then it's all about determining what are the marital (or joint) assets and debts, and then how to split them.
If there are joint credit cards, then get them paid off and close the accounts. (Joint could be particularly difficult to manage since one can ask the account to be suspended and the other can just call up and might be able to get it reactivated.)
Other cards are under the account holder's full control, if your spouse is a card holder on your accounts you can close out his cards. And he can do the same to you.
Yes, do try to steer clear of the emotional wrangling and maneuvers. Of short duration and without children, this unwinding can and should largely be handled in a businesslike manner.
Are there any joint assets, joint debts or other issues? Pets? Vehicles? House or leases? (That he moved out makes it less likely he will hold your residence for emotional ransom or leverage.)