Suggestion: the entire plot with super-Hermione is Voldemort's practise at being nice. But he's not being nice to Hermione, he's being nice to Harry. He reasoned that this is a better way of stopping Harry destroying the stars than simply killing him (this way carries a slight risk but stops him having to kill his friend). He simply didn't see it because is was a 'nice' method.
This would explain the extravagance of the immortality mechanisms he's giving Hermione.
Not quite an either/or--perhaps he's also testing the immortality mechanisms he will use on himself. It hadn't occurred to me, but he may not be as confident as he pretends to be about how the Stone and the troll/unicorn/Horcrux spells will interact. And it closely parallels his previous failure to test his Horcrux system.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 111.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: