As I said previously, Table of Contents navigation is supported in V5, you can navigate to whatever chapter you choose from the menu.
I've done further checking on support for endnotes navigation in V5, and it isn't supported for fb2, either. It's not a problem as far as I am concerned, I find these endnotes distracting and never follow the links to read them
I discovered, however, that fb2 files have a settings sub-menu (which doesn't appear to exist for any other file formats) where you can set default font face, font size (not zoom), spacing between the lines and a few other things. I wish V5 had these options for other file formats ...