Since we use normally use indexmenu for our sidebar, and since SiteExport and Epub no longer seem to work properly with indexmenu, I have tried putting a sidebar page in the opencpn:manual_basic namespace and hard coding the page links there, just as if it were a hard coded TOC. Then with that sidebar page open, and selecting Admin and then SiteExport, and then try to export the pages, and at least the plugin exports the pages intended with links to each page.
So now the problem is to get the website wiki to complete 147 pages without having a "timeout"
OR to get the offline, local version to work without having it show Status: Download Failed.
So in short, there is a way to hard code the sidebar. And you can put a sidebar page in any namespace.