Linkit Module - Pointing the link's title attribute to a custom field. Hook available?

Currently the Linkit module delivers the link's title attribute by pulling the related node's title field.

We would like it to point to another field in the node.

How can we achieve this?

I looked into Editor Advanced Link module, but I need this to be automatic, and my custom field changes based on content type.

Maybe someone has a hook idea?

There are (at least) 2 options:

1. Write a custom filter plugin, basing it on the LinkitFilter plugin included with the Linkit module. In the process() method, where the title is currently set, introduce you own logic to set the title field instead of the existing $entity->label().
   
   This method has the benefit of auto-updating when a referenced node's title changes, but does mean you'll have to maintain your filter alongside the Linkit module's releases. The process() method does a lot more than just setting the title, and new features/bug fixes in the module will need to be incorporated into your code.

2. Alter the link dialog form (like Editor Advanced Link does), and get the title into the markup while it's still in the editor. This method is a bit easier, and less maintenance, but the title attribute won't update when the node title does. It will only update when the link dialog form is saved again.
   
   If that's acceptable, this is a rough but working example to get started:

   use Drupal\Core\Form\FormStateInterface;
   use Drupal\node\NodeInterface;
   
   function custom_module_form_editor_link_dialog_alter(&$form, FormStateInterface $form_state, $form_id) {
     array_unshift($form['#validate'], '_custom_module_link_dialog_validate');
   }
   
   function _custom_module_link_dialog_validate(array &$form, FormStateInterface $form_state) {
     $attributes = $form_state->getValue('attributes');
   
     if (isset($attributes['data-entity-type']) && $attributes['data-entity-type'] == 'node') {
       $node = \Drupal::service('entity.repository')
         ->loadEntityByUuid('node', $attributes['data-entity-uuid']);
       if ($node instanceof NodeInterface) {
         $override_title = '';
         switch ($node->getType()) {
           case 'page':
             $override_title = $node->field_title_override->value;
             break;
           case 'foo':
             // ...
             break;
         }
         if (strlen($override_title)) {
           $form_state->setValue(['attributes', 'title'], $override_title);
         }
       }
     }
   }