It does sounds great - but as we cannot actually install exception handlers, you are really talking about increasing awareness and knowing what reactions to take. Which typically comes from... talking to a therapist.
But therapists know when the client really needs a different therapist, or a full psychologist, and can flag behaviors that are truly dangerous, psychosis, etc. They also know when someone is pushing too hard and aren't yet ready for their next therapeutic steps. There is a lot more to what they do than just flagging behaviors and handing out tools, questions, and answers.
While I think that it could be amazing if you pull it off, I don't want it for the same reason I don't want any experimental medical treatment - I would be putting my health at risk just to see if your idea works, and that is not something I want to sign up for.