This type of ‘cure’ for dysmorphia is not something to be celebrated.
But ultimately the end result seems to be that they will eventually, one way or another, find a way to get the surgery they desire. I don't know what your solution would be in that scenario other than to criminalize it and even then, there's reports of people doing home made amputations by sitting on rail tracks or whatever else you can think of.
And that is....? There is no psychological treatment that cures BIID and the patient here seems very happy. Is it really better and "proper" to give someone treatment that doesn't solve their problem and leaves them upset?
I'm convinced that my overall quality of life would improve if I got the disability I desire. The mental anguish is simply more intense than the consequences of physical limitation. I personally know others who have "gone through with it" and they really are happier now.
Also, FWIW, I'm sorry for your condition. It sounds hellish.
my case is kind of special, since I also have a progressive genetic disorder that's led to me being disabled. it affects me in some of the ways that I "want", but not as completely as I'd like, and causes other issues I never wanted at all.
I attempted to integrate like you suggest, shifting my BID towards the direction of my newfound disability. mostly using cognitive reframing, acceptance/commitment therapy, and working at the peripheral issues like imposter syndrome, shame, grief.
I feel much less shame now, and I'm able to use BID as a coping mechanism for my physical condition, but the darned dysphoria is still present.