WTF, mate? If you've been at the end of a Harry Potter book, you'd never ever want to go to a bookmark in the middle ever again. How dare you question Discourse's amazingness????!!!!11eleven
... wow it's even worse how he actually said it.
Well, they will need to learn that once you have read a book to the end, that is how it works.
Actually Jeff, here's how it works when you read a book: you stick your finger in a spot, flip back and forth, and then come back to wherever you stuck your finger. Amazingly, this even works if you've read the book in its entirety, or even if you only just told it that you had read the whole thing.
I'd like to re-read one again
That is an argument for "reset my read state in this topic" which strikes me as quite an advanced thing to need.
a) no not really
b) it strikes me as something that isn't very advanced, that many forums provide, and that should be much easier to implement than importing issues from Github.
But that's just my unwanted two cents of common sense.