Personally, the Notes I want to keep track of are for recipes I have access to -- either in books already on my Bookshelf or online recipes that can be added to my Bookshelf -- so I tend to Bookmark those recipes with one of my various "to try" bookmarks and consult the Notes for that recipe again before actually making it. Maybe you could try creating a specific bookmark for recipes with interesting Notes? If the recipe has a lot of Notes, you could add your own personal note (by checking the "Make this a personal note?" box) to remind yourself of the username of the member whose Note you wanted to refer back to.
Obviously, this does not help if you are also trying to keep track of Notes for recipes from books you don't own, but are maybe considering adding to your collection.