Rated 5 out of 5 stars

I want to use this extension not only gone pages but also 404 page.

This review is for a previous version of the add-on (0.8.1). 

Simply ignore it

If you do not want to use the functions of EZP in HTTP 404 pages, simply ignore it. I believe it is not so painful to see some more buttons. The auto retry function is enabled only for timeout pages by default.