I understand what you're claiming, as I pointed out under this understanding your current existence is already terrifying. Not just when you fall asleep, but even moment by moment the underpinning compute substrate is repaired and replaced and yet it feels as though this is an ongoing experience, there's no reason Yorkie experiences this any differently even though intellectually she knows the transformation was more... substantial.
It's just Trigger's Broom / the Ship of Theseus, this isn't even a new idea.
> the writers place a lot of not so subtle hints as to the idea that it isn't.
Like the hint where Charlie Brooker specifically said that no it's the Happily Ever After ending ? Maybe he wasn't patting his head like you knew he would be if he was addressing True Fans like you ? Didn't give the secret sign ?
I thought I already spelled this out well enough, that somebody will insist that the heroes are villains, that the bad guys are the good guys and so on. Sometimes they have a point, but more often they just didn't see what was in front of them. I am kinda tangentially interested in the Slash scene (e.g. I know people involved in AO3) and the Slash communities are the same - sometimes you're like sure, this was barely subtext in the movie/ TV show/ novel, in a braver world the writers would have had them kiss on camera, but other times it's like "Where did this even come from? Were you watching the same show?" - and sometimes that's deliberate contrariness but other times it really isn't.
It's not as though I don't have my own divergences from what writers believe about their own works - for example in my opinion Firefly was a TV show about the bad guys (people who lost a civil war and just decide that doesn't count) written by someone who doesn't understand that they're the bad guys. Obvious Whedon doesn't agree and I don't expect him to. Or for example Vinge insisted he doesn't know who/what Rabbit is in "Rainbows End" and in my opinion there's only one option which makes any sense.
But I guess I kinda asked for people to insist their wrong interpretations of San Junipero are the only correct one when I gave the example.
Sure, we can go into sleep and is reality even real. But it's a bit different when we're talking about a specific reality we know is not real and the point I'm getting at is that we know that version of you is for sure 100% with no uncertainty not you. Since both entities can exist simultaneously and independently. Which is an entirely different construct than say dying in your sleep and being replaced because there's not multiple entities with shared experiences existing at the same time. What I'm pointing to is this so yeah there's clearly miscommunication when you're talking about an even more abstract concept.
I haven't seen the newer seasons. But looking at the synopsis on wiki (Beyond the Sea?), this is a very different scenario. Permutation City might be a better one to look at for what I'm getting at. Remember in that story that you are essentially making a copy of yourself and putting it into that universe. That entity is not you, but it is sentient, conscious, and it's own thing. But you aren't in that simulation with it unless you virtually go in (and in their scenario you need to deal with the time differential).
San Junipero is a corporation promising you life after death. The same way Amazon Prime's Upload does. But San Junipero in Black Mirror itself made no claim, and the writers place a lot of not so subtle hints as to the idea that it isn't. Not only by nature of being a Black Mirror episode, but I suggest you look closer at the soundtrack of the episode and how its used in context.