I have a good education, and I am opposed from my own ethical stance to allowing character disorders (personality disorders) to be considered legal insanity. I'm also opposed to it from a procedural and legal point of view. However, I still find CO's system and the general NGRI defense puzzling.
But I know that Borderline PD has been used successfully for a NGRI defense (because Borderline PD can include episodes of psychosis, often repeated and on the shorter term side, often snapped back to reality by the other inner demands of the psyche of the Borderline personality).
I think Dr L did say that DID and Borderline resemble each other (yes, indeed they do). Borderlines may have amnesia for the psychotic episodes, but in DID, the amnesia is only experienced by some personalities with the "main personality" often having the amnesia. In DID, the amnesia is explained by disassociation rather than psychosis (usually). Since there are no brain studies (that I know of and I've looked) of someone actively experiencing psychosis during either of these conditions, I don't know what to say about it. We have brain studies of schizophrenics, as a contrast. And bipolars. And depressives.
Since most acts of extreme violence (I would say excepting those committed by ASPD/sociopaths) are conducted in some kind of altered state (my opinion), it's a slippery slope. I think the whole insanity defense should spin around totally involuntary and unwitting mental states, by which the person's brain (through a longterm brain defect) renders them incapable of knowing they are eating someone's face or that they just killed someone they loved (in a paranoid state, thinking that person was a space alien or whatever). Even then, I'm not sure why we need a separate sentencing system for them (most prisons have psych wards, and if a state doesn't have a prison psych ward, they should make/build one if they're going to have this "they can get out when they're better" rubric).
Not all states have that rubric. In California, we still sentence NGRI defendants as required by law, they just serve their time elsewhere than a state prison (a state mental hospital - we have a couple of them). If they get better, they can go to prison (IME, they prefer to stay at the hospital and for good reasons). Also, in California, the determination about sanity is made by either the Court or by the Jury.
But we do not let them out once they get better, they have to serve their allotted time.
IMO.