For transplant/transfusion ('sleeving', if/when we do pull off mind-uploading), as artificial wombs. Genetically modified pigs is a fine idea, but why not cut to the chase? If anything it would be far more ethical than sacrificing the pig, who has actual unique metaphysical content (and really quite a bit, relative other animals), vs the anencephalic which has essentially NONE whatsoever, less than any functional vertebrate. And it could be done starting immediately. And the sooner we start the sooner the utility is realized (they still need time to grow). How is it NOT already being done? How do we get the ball rolling on this?

Is it really just broken 'humans are special because we're us' moral-instinct masquerading as ethics, or are there known/likely practical barriers I am unaware of as a layman?

I am dead serious about this. How the fuck do we make this happen? Help me make this happen.