function ds_exclude_misc_everywhere( $query ) {

    // Homepage feed (main query only)
    if ( $query->is_home() && $query->is_main_query() ) {
        $query->set( 'category__not_in', array(3) );
    }

    // Chronological feed page (main query only, detected by slug)
    if ( !is_admin() && $query->is_main_query() && $query->is_page('start-from-the-beginning') ) {

        // Force this page to behave like an archive instead of a Page
        $query->set( 'post_type', 'post' );
        $query->set( 'page_id', '' );
        $query->set( 'pagename', '' );

        // Exclude Category 3
        $query->set( 'category__not_in', array(3) );

        // Oldest → newest
        $query->set( 'order', 'ASC' );
        $query->set( 'orderby', 'date' );
    }
}
add_action( 'pre_get_posts', 'ds_exclude_misc_everywhere' );
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://dailysuperman.com/wp-sitemap-index.xsl" ?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><sitemap><loc>https://dailysuperman.com/wp-sitemap-posts-post-1.xml</loc></sitemap><sitemap><loc>https://dailysuperman.com/wp-sitemap-posts-page-1.xml</loc></sitemap><sitemap><loc>https://dailysuperman.com/wp-sitemap-taxonomies-category-1.xml</loc></sitemap><sitemap><loc>https://dailysuperman.com/wp-sitemap-taxonomies-post_tag-1.xml</loc></sitemap><sitemap><loc>https://dailysuperman.com/wp-sitemap-users-1.xml</loc></sitemap></sitemapindex>