Actually, the post type and taxonomies are hidden from view but they do already exist.
The taxonomy is set in class-wprm-taxonomies.php and post type is in class-wprm-post-type.php. Setting them to work with menus and widgets is just a case of editing the options used to register the post type and associated taxonomies. When the necessary changes are made the recipe titles still redirect to their parent page so SEO duplicate content warnings should not occur.
What is your opinion of the following changes:
Set post type args in class-wprm-post-type.php to:
$args = apply_filters( 'wprm_recipe_post_type_arguments', array(
'labels' => $labels,
'public' => true,
'rewrite' => false,
'capability_type' => 'post',
'query_var' => true,
'show_ui' => true,
'show_in_nav_menus' => true,
'supports' => array('title','editor','custom-fields','revisions'),
'taxonomies' => array('wprm_course','wprm_cuisine','wprm_ingredient'),
));
Set taxonomy args in class-wprm-taxonomies.php to:
foreach ( $taxonomies as $taxonomy => $labels ) {
$args = array(
'labels' => $labels,
'hierarchical' => true,
'public' => true,
'show_ui' => true,
'query_var' => true,
'rewrite' => true,
'show_in_rest' => true,
'show_ui' => true,
'show_in_nav_menus' => true,
'has_archive' => true,
);
I guess edits here would improve compatibility with WPML, too, e.g. enable the the default editor admin pages for this post type but replace the main content editor (currently fills with the recipe Notes content block) with styled custom fields.