I think my lack of reaction to his crap is precisely the reason for his ever increasing lies/accusations & emotional dysregulation
He's not getting the response he wants from me so he ups the ante.
This is my experience. I think the key is understanding what he's doing, that it's part of a method of madness, and that you don't have to engage it. That doesn't mean it isn't totally exhausting and frustrating, but you don't have to engage it.
He can't sustain this facade with everyone, indefinitely. My ex, which I've told you about before, has his enablers and believers. But a lot of people see him for what he is and act accordingly.
The courts? They can't punish someone for being an *******. Assholes still have rights and everything, and as long as they stay on *this side* of the law, their hands are tied. If your AH EVER BREAKS THE LAW, call the police and let the chips fall where they may. This was also my experience with my ex, and over time he exhausted all goodwill from the courts, the police, and his enabling lawyer. It took a few years.