Declare variables for enabled providers

I managed with Hybridauth 2.9 to declare variables in a custom module, not in a fancy way, but fair enough to solve my problem of using different configurations of hybridauth when using Domain Access (aka several domains). It was all like this:

function MYMODULE_variable_info($options = array()) {
  $variables['hybridauth_provider_Facebook_enabled'] = array(
    'title' => t('Facebook enabled', array(), $options),
    'description' => t('Is facebook enabled', array(), $options),
    'type' => 'number',
    'default' => 0,
    'group' => 'hybridauth',
    'multidomain' => TRUE,
  );
  $variables['hybridauth_provider_Facebook_keys_id'] = array(
    'title' => t('Facebook key ID', array(), $options),
    'description' => t('Facebook key ID', array(), $options),
    'type' => 'string',
    'default' => NULL,
    'group' => 'hybridauth_facebook',
    'multidomain' => TRUE,
  );
  $variables['hybridauth_provider_Facebook_keys_secret'] = array(
    'title' => t('Facebook key secret', array(), $options),
    'description' => t('Facebook key secret', array(), $options),
    'type' => 'string',
    'default' => NULL,
    'group' => 'hybridauth_facebook',
    'multidomain' => TRUE,
  );
  $variables['hybridauth_provider_Google_enabled'] = array(
    'title' => t('Google enabled', array(), $options),
    'description' => t('Is Google enabled', array(), $options),
    'type' => 'number',
    'default' => 0,
    'group' => 'hybridauth',
    'multidomain' => TRUE,
  );
  $variables['hybridauth_provider_Google_keys_id'] = array(
    'title' => t('Google key ID', array(), $options),
    'description' => t('Google key ID', array(), $options),
    'type' => 'string',
    'default' => NULL,
    'group' => 'hybridauth_google',
    'multidomain' => TRUE,
  );
  $variables['hybridauth_provider_Google_keys_secret'] = array(
    'title' => t('Google key secret', array(), $options),
    'description' => t('Google key secret', array(), $options),
    'type' => 'string',
    'default' => NULL,
    'group' => 'hybridauth_google',
    'multidomain' => TRUE, 
  );
 // and so on with every provider I want to manage
  return $variables;
}

/**
 * Implements hook_variable_group_info().
 */
function MYMODULE_variable_group_info() {
  $groups['hybridauth'] = array(
    'title' => t('HybridAuth'),
    'description' => t('Oauth variables.'),
    'access' => 'administer domains',
    'path' => array('admin/config/people/hybridauth'),
  );
  $groups['hybridauth_facebook'] = array(
    'title' => t('HybridAuth Facebook'),
    'description' => t('Oauth variables.'),
    'access' => 'administer domains',
    'path' => array('admin/config/people/hybridauth/provider/Facebook'),
  );
  $groups['hybridauth_google'] = array(
    'title' => t('HybridAuth Google'),
    'description' => t('Oauth variables.'),
    'access' => 'administer domains',
    'path' => array('admin/config/people/hybridauth/provider/Google'),
  );
 // and so on with every provider I want to manage
  return $groups;
}

However with the new 2.10 version and #2303237: Remove plenty of variables new "enhancement" I'm screwed again :(
Since the "enabled" is now embedded in an array, I'm not able to declare the array variable and save independent values for each domain.
I have tried to use something like this but it ain't worked.

  $variables['hybridauth_providers'] = array(
    'title' => t('Hybridauth Providers', array(), $options),
    'description' => t('is providers enabled', array(), $options),
    'type' => 'array',
    'default' => array(),
    'group' => 'hybridauth',
    'multidomain' => TRUE,
  );

I could then declare the variable in a domain realm, but neither

• admin/config/people/hybridauth show the domain selector,
• or admin/structure/domain/view/3/variables allow to input any value

Any clue please ?