Can not use the formatters and widgets for primitive fields if entity is fieldable=FALSE

I am just trying to use existing widgets and formatters for my own lightweight entity, written with fieldable=FALSE.

I don't want to write megatons of FormAPI code and save and constrain (validation) logic for the entity with simple string/text/integer fields > 10.

I implement in mymodule.module:

/**
 * Implements hook_field_widget_info_alter().
 */
function mymodule_field_widget_info_alter(&$info) {
  $info['text_textfield']['field_types'][] = 'integer';
  $info['text_textfield']['field_types'][] = 'string';
}

/**
 * Implements hook_field_formatter_info_alter().
 */
function mymodule_field_formatter_info_alter(&$info) {
  // Let a new field type re-use an existing formatter.
  $info['text_default']['field types'][] = 'integer';
  $info['text_default']['field types'][] = 'string';
}

Then define the entity:

/**
 * @file
 * Contains Drupal\mymodule\Entity\MyEntity.
 */

namespace Drupal\mymodule\Entity;

use Drupal\Core\Entity\ContentEntityBase;
use Drupal\Core\Field\FieldDefinition;

use Drupal\mymodule\myentityInterface;

/**
 * Defines the myentity.
 *
 * @EntityType(
 *   id = "myentity",
 *   label = @Translation("myentity"),
 *   module = "mymodule",
 *   controllers = {
 *     "storage" = "Drupal\Core\Entity\FieldableDatabaseStorageController",
 *     "view_builder" = "Drupal\Core\Entity\EntityViewBuilder",
 *     "access" = "Drupal\Core\Entity\EntityAccessController",
 *     "list" = "Drupal\mymodule\myentityListController",
 *     "form" = {
 *       "default" = "Drupal\mymodule\myentityFormController",
 *     },
 *   },
 *   base_table = "myentity",
 *   fieldable = FALSE,
 *   entity_keys = {
 *     "id" = "eid",
 *     "label" = "Name",
 *   }
 * )
 */
 
 class MyEntiy extends ContentEntityBase implements MyEntiyInterface {

  /**
   * {@inheritdoc}
   */
  public static function baseFieldDefinitions($entity_type) {
    $fields['eid'] = FieldDefinition::create('integer')
      ->setLabel(t('MyEntiy ID'))
      ->setDescription(t('The MyEntiy ID'))
      ->setRequired(TRUE)
      ->setReadOnly(TRUE);

    $fields['uuid'] = FieldDefinition::create('uuid')
      ->setLabel(t('UUID'))
      ->setDescription(t('The MyEntiy UUID.'))
      ->setRequired(TRUE)
      ->setReadOnly(TRUE);

    $fields['Name'] = FieldDefinition::create('string')
      ->setLabel(t('MyEntiy name'))
      ->setDescription(t('The MyEntiy name.'))
      ->setRequired(TRUE)
      ->setSettings(array(
        'default_value' => '',
        'max_length' => 128,
        'text_processing' => 0,
      ))
      ->setDisplayOptions('form', array(
        'type' => 'text_textfield',
        'weight' => -5,
      ))
      ->setDisplayConfigurable('form', TRUE)
      ->setPropertyConstraints('value', array('Length' => array('max' => 128)));

      // ...SOME OTHER FIELDS... //
 }