[DiapDealer]

I'm not sure that makes sense, Roger. This plugin creates a new xhtml file out of an image you specify. It doesn't change any existing files and it has no preconceived notions about what you want to do with the newly created one (SVG wrapped images can occur anywhere on an epub). Once this new xhtml file has been created, it's up to you (the user) to decide if it is to be used as the cover page, or if it needs to be included in any html toc or nav documents, or what-have-you.

If you're looking to modify an existing cover page in an epub, I suggest using the built-in Tools->Add Cover feature of Sigil. It will take an image of your choosing, wrap it in an SVG and either create a new cover.xhtml (if no cover-page is already defined), or it modifies an existing cover page (if one is already defined). All pre-existing links would remain intact.