Cannot use ds fields in form

I expected to use ds fields in ds_form. Source tells me this does not work yet.

function ds_field_ui_fields_layouts(&$form, &$form_state) {
...
  // Add/alter fields on the table, but only if a layout is selected.
  if ($view_mode != 'form' && !empty($form['#ds_layout'])) {
    _ds_field_ui_fields($entity_type, $bundle, $view_mode, $form, $form_state);

We should really enable that to enrich forms.