Generating Rewrite Rules for Custom Post Type

Hi,

I am developing for a website where I create some Custom Post Types and som Custom Taxonomies.

I am trying to modify the default WP URLs where the CPT slug is at the beginning.

Imagin my CPT is book.

I want my URLs to change from example.com/book/great-book-title to example.com/fantasy/great-book-title (where fantasy is the slug of a term of a custom taxonomy).

There are two reasons for this:

1. I have no archives page, so example.com/book/ is not used
2. I use Polylang to make it multilingual, but “book” would be in all my URLs

What I did:

1. I filter the CPT URL to match my structure
2. I add rewrite rules on the top to capture my posts

The issue:
I created rewrite rules, but then I realised I was missing example.com/fantasy/great-book-title/feed or example.com/fantasy/great-book-title/trackback…

I saw what WP was trying to create and I use this function to create the rewrite rules:

function cbm_create_all_rewrite_rules_versions($regex, $query_var, $match_num){

    $second_match_num=$match_num + 1;

    /*Post itself*/
    add_rewrite_rule('^' . $regex . '/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']', 'top');
    /*Feeds*/
    add_rewrite_rule('^' . $regex . '/feed/(feed|rdf|rss|rss2|atom)/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']&feed=$matches['. $second_match_num . ']', 'top');
    add_rewrite_rule('^' . $regex . '/(feed|rdf|rss|rss2|atom)/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']&feed=$matches[' . $second_match_num . ']', 'top');
    /*Embed*/
    add_rewrite_rule('^' . $regex . '/embed/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']&embed=true', 'top');
    /*Trackback*/
    add_rewrite_rule('^' . $regex . '/trackback/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']&tb=1', 'top');
    /*Paged*/
    add_rewrite_rule('^' . $regex . '/page/?([0-9]{1,})/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']&paged=$matches[' . $second_match_num . ']', 'top');
    /*Comment-page*/
    add_rewrite_rule('^' . $regex . '/comment-page-([0-9]{1,})/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']&cpage=$matches[' . $second_match_num . ']', 'top');
    /*Page*/
    add_rewrite_rule('^' . $regex . '(?:/([0-9]+))?/?$','index.php?' . $query_var . '=$matches[' . $match_num . ']&page=$matches[' . $second_match_num . ']', 'top');

}

Is there a way to make WP generate all these possibilities?