Anything will reinforce the feedback loop. That’s inherent in the disorder. Either they voluntarily seek help, they are involuntarily committed, or they do not seek help. You can’t pressure them. They will rationalize their decision without any regard for the reality you perceive. Eventually, you can only choose either to enable them or to shun them.

I think this is very dehumanizing and assumes the worst. I guess I don't have too huge a dataset, but I have seen it be the case that they know something is wrong even if they're not super eager to admit it, and even if they have a strong delusion they won't otherwise let go of. If they are on the fence about it, shunning will tip them over in the wrong direction.

It’s your right to try and act as a counselor to them, but it’s also your right not to. If you are emotionally invested in their welfare for personal reasons, that will absolutely skew your priorities away from shunning. So will the sunk cost fallacy.

The hardest thing to do is to protect yourself when those circumstances are combined, and someone is this close to getting over the hump, and it’s infinitely worse when they’re family/friend. I’m sorry you had to live through that, no matter what you chose.

I have done both things at different times with different people. Lately, after some recent experiences, I err strongly on the side of letting go of myself, abandoning any pretense, and trying to be unconditionally supportive. I would make some attempt to do that even if I were not especially close to the person. A lot of people tell me they don't feel comfortable extending themselves in that way and that is fine, but I have decided it is the ideal we should aspire to.