我已经回答了一个类似的问题（Inherit plugin settings to new site in Multisite ).

而且，如果理解正确，“自动设置其唯一首选项”将是在wp_options 桌子

因此，遵循WP Pagenavi示例。插件自动安装/激活后，运行如下操作：未测试

function set_my_plugin_options(){
    $defaults = array(
        \'pages_text\'                    => \'Page %CURRENT_PAGE% of %TOTAL_PAGES%\',
        \'current_text\'                  => \'%PAGE_NUMBER%\',
        \'page_text\'                     => \'%PAGE_NUMBER%\',
        \'first_text\'                    => \'« First\',
        \'last_text\'                     => \'Last »\',
        \'prev_text\'                     => \'«\',
        \'next_text\'                     => \'»\',
        \'dotleft_text\'                  => \'...\',
        \'dotright_text\'                 => \'...\',
        \'num_pages\'                     => 5,
        \'num_larger_page_numbers\'       => 3,
        \'larger_page_numbers_multiple\'  => 10,
        \'always_show\'                   =>,
        \'use_pagenavi_css\'              => 1,
        \'style\'                         => 1
    );
    update_option( \'pagenavi_options\', $defaults );
}