Save node via ajax continuously
So I managed to figure it out myself. It just seems that you need to build up the whole new form state manually and then rebuild the form with that state again. Here's my modified code for the ajax submit handler. But if anyone still has a better solution please post your answer here.

function MYMODULE_finding_node_form_submit_ajax($form, &amp;$form_state){
  $commands = array();
  $commands[] = ajax_command_remove('.l-messages');
  if(form_get_errors()){
    $commands[] = ajax_command_replace(NULL, drupal_render($form));
  }
  else{
    $node = $form_state['node'];
    $new_form_state = array();
    $new_form_state['build_info']['args'][] = $node;
    $new_form_state['no_redirect'] = TRUE;
    $new_form_state['input'] = array();
    $new_form_state['values'] = array();
    $new_form_state['method'] = $form_state['method'];
    $new_form = drupal_rebuild_form('finding_node_form', $new_form_state);

    $commands[] = ajax_command_replace(NULL, drupal_render($new_form));
  }
  $commands[] = ajax_command_prepend('.page', '&lt;section class="l-messages row"&gt;&lt;div class="columns"&gt;' . theme('status_messages') . '&lt;/div&gt;&lt;/section&gt;');

  return array('#type' =&gt; 'ajax', '#commands' =&gt; $commands);
}