It does not seem to be possible to load the next page for the plugin index on https://imagej.net/Category:Plugins
It comes up with: The requested URL was not found on this server. The first page does only show plugins up to the beginning of letter “S”
… that should contain the entire list. The links will lead to pages that might still lack some content, but as a workaround you can take the page title and use it with the https://imagej.net/ domain to access the original (currently read-only) wiki page.