Custom REST routes for api-prefixed route (does not respect Accept Header)

gistfile1.php

/**
 * Prefixed API routes (served using Crud.ApiListener).
 */
Router::prefix('api', function ($routes) {

    //  Enable .json extension parsing
    $routes->extensions(['json', 'xml']);

    /**
     * API index route.
     */
     $routes->connect(
         '/:controller',
         [
           'action' => 'index',
           '_method' => 'GET',
           '_ext' => ['json', 'xml'],
        ]
    );

    /**
     * API view route.
     */
    $routes->connect(
        '/:controller/:id',
        [
           'action' => 'view',
           '_method' => 'GET',
           '_ext' => ['json', 'xml'],
        ],
        [
           'id' => self::ID . '|' . self::UUID,
           'pass' => [
               'id',
           ]
        ]
    );

    /**
     * API add route.
     */
    $routes->connect(
        '/:controller',
        [
           'action' => 'add',
           '_method' => 'POST',
           '_ext' => ['json', 'xml'],
        ]
    );

    /**
     * API edit route.
     */
    $routes->connect(
        '/:controller/:id',
        [
           'action' => 'edit',
           '_method' => 'PUT',
           '_ext' => ['json', 'xml'],
        ],
        [
           //'id' => '@todo: someUuidRegEx for more strict checking',
           'id' => self::ID . '|' . self::UUID,
           'pass' => [
               'id',
           ]
        ]
    );

    /**
     * API delete route.
     */
    $routes->connect(
        '/:controller/:id',
        [
           'action' => 'delete',
           '_method' => 'DELETE',
           '_ext' => ['json', 'xml'],
        ],
        [
           //'id' => '@todo: someUuidRegEx for more strict checking',
           'id' => self::ID . '|' . self::UUID,
           'pass' => [
               'id',
           ]
        ]
    );

   // No fallback routes for the API, all non-matches should 404
});