RouteInModalAjaxHelper::ajaxCallback, inline form errors and messages

Problem/Motivation

In RouteInModalAjaxHelper::ajaxCallback, in case of form errors and when the inline_form_errors module is present, all messages are deleted:

if ($moduleHandler->moduleExists('inline_form_errors')) {
        // Refresh form with inline errors.
        $response->addCommand(new HtmlCommand('#route_in_modal_wrapper', $form));

        // Delete default messages.
        \Drupal::messenger()->deleteAll();
 }

This assumes that all present messages are corresponding the inline form errors. This however might not always be the case.
For example, a form with valid data that is submitted and something fails during submit. Such errors are now removed an never reach the end user.

Proposed resolution

Ideally, only the messages corresponding to inline form errors should be removed. If that is not possible, better show all messages then none (imo).