Bookmarks could be a dark horse.  Right now my bookmarks are basically write-only; I've never actually used them on any platform.  Maybe this could drive that use case.

elvismercury

Feature idea: perpetually-editable SN posts

I wonder if making them cost more than normal posts would alleviate people's concerns. 

Also, if you don't want these posts to reenter the feed every time you update, it seems like people aren't going to see them. Although, maybe we'll just make more use of our bookmarks.

I think this is a promising idea.