With the current limit in Elite Dangerous to total number of saved bookmarks, keeping long distance routes becomes unreasonable. As our saved bookmarks quickly become cluttered with routes. This was my solution to keep the bookmark list clean, but still have an ability to save long distance routes out of the game that we can import quickly when we want to use them.
All details and instructions have been saved on the following site.
https://sites.google.com/view/ed-auto-bookmark