How can I remove or overwrite the YAML validation from a Webform Entity?
I was able to achieve this, thanks to some guidance in the comments, by overriding a service.

This involved work in two custom module files.  The first was modules/custom/mymodule/src/MymoduleFormParserServiceProvider.php

Within that file I used ::alter to alter which class is called for a particular service.

&lt;?php

namespace Drupal\mymodule;

use Drupal\Core\DependencyInjection\ServiceProviderBase;
use Drupal\Core\DependencyInjection\ServiceProviderInterface;
use Drupal\Core\DependencyInjection\ContainerBuilder;

/**
 * Replace Webform validator service.
 */
class MymoduleServiceProvider extends ServiceProviderBase implements ServiceProviderInterface {

  /**
   * {@inheritdoc}
   */
  public function alter(ContainerBuilder $container) {
    $definition = $container-&gt;getDefinition('webform.elements_validator');
    $definition-&gt;setClass('Drupal\mymodule\MymoduleWebformElementsValidator');
  }

}


What this does is tell Drupal that when the webform.elements_validator service is called, use the MymoduleWebformElementsValidator class instead.

The second piece of the puzzle was to create that class.  I did that by extending the original class WebformEntityElementsValidator with my own MymoduleWebformElementsValidator class and doing the logic there.  That way I was able to keep most of the validation from the original, but make the changes to the validate method that were needed.

I was able to find many of the answers after googling override service thanks to the comment on the question by @jrockowitz