The point is that an exact copy of me from another universe is not me, ergo an exact copy of me in this universe still isn't me.

none of that makes any sense, less thesaurus words and more words off the back of a cereal box pls.

What i think youre saying is that conciousness doesnt really exist, and it just a trick our minds play on ourselves. And to that i say its just way too philosophy brained for it to have any real world application, especially in the original context of helping terminal patients. How does it help someone who is dying if someone who shares all of their memories and their personality if theyll just die in a couple weeks? Sure it may be helpful to family both emotionally and materially if they were dependant on the person who is dying, but it doesnt help the actual person, the one who persists after the process. Hey healthy me, be good to my family and have a nice life, then flatline. That one is dead, they were a living, feeling person who died, all that was accomplished is they gave birth to a very similar person to themself, but they still experienced death and now theyre gone forever.

just cut pasting someone isnt really them, since the paste is the same whether it was a cut paste or copy paste. it all feels like immortality cope. Yeah i wish it were that easy, and its the kind of immortality scifi often portrays because its the closest to being possible with our current technology, but perhaps a different way would remove some doubt as to whether you actually survive the process. Your brain is continuously rewiring, connecting and disconnecting neurons, all day every day in situations no one would believe to be your death or disappearance. Perhaps if you give your brain access to new neurons, perhaps synthetic, nanotechnology of sorts with more resillience that biological neurons, your brain could by its natural process of rewiring integrate those into your brain, while disconnecting the dying biological neurons, with time, your brain would be entirely constructed of synthetic neurons, which would allow for further integration with synthetic bodies, as they were designed by humans and thus fully compatible with a brain to machine interface. If the mind copy you describe is like crashing a program on one computer, then starting that same program on another computer, this gradual neuron replacement method is like plugging in a big new stick of RAM, then letting running programs move their processes over onto the new RAM uninterrupted, and disconnecting the old broken ram only when it has become completely unutilized.