When I use to use my ED80 visually (which was rarely) fortunately I had a 2" Barlow that I didn't use so I just unscrewed the lens from it and used the rest as a 2" extension tube.
Then I discovered that the ED100 focuser is a perfect fit and is waaayyyyy longer so it is great for visual work in the ED80
That gives you 2 options: Extension tube or ED100 focuser.