ElasticPress exclude post type from "Weight results by date" decay

functions.php

<?php

/**
 * Filter the arguments sent to EP query
 *
 * @param array $formatted_args Formatted Elasticsearch query
 * @param array $query_vars Query variables
 * @param array $query Query part
 *
 * @return array
 */
function filter_ep_args( $formatted_args, $query_vars, $query ) {
  
  // Only apply this to the main search query.
  if ( ! is_search() && ! is_main_query() ) {
    return $formatted_args;
  }
  
  // Get the ElasticPress search settings.
  if ( defined( 'EP_IS_NETWORK' ) && EP_IS_NETWORK ) {
	$ep_feature_settings = get_site_option( 'ep_feature_settings', [] );
  } else {
	$ep_feature_settings = get_option( 'ep_feature_settings', [] );
  }
  
  // Make sure "Weight results by date" is enabled.
  if (
	'1' === $ep_feature_settings['search']['decaying_enabled'] &&
	! empty( $formatted_args['query']['function_score']['functions'] ) &&
	is_array( $formatted_args['query']['function_score']['functions'] )
  ) {
	// Existing decay definition should be here.
	$decay = $formatted_args['query']['function_score']['functions'][0];

	// Add only the post types that should have the decay applied.
	$extra_filter = [
		'filter' => [
			'terms' => [
				'post_type.raw' => [
				      'post_type_1',
				      'post_type_2'
				],
			],
		],
	];

	// Add both decay and the new filter to the query.
	$formatted_args['query']['function_score']['functions'][0] = array_merge(
		$extra_filter,
		$decay
	);
  }
}

add_filter( 'ep_formatted_args', 'filter_ep_args', 10, 2 );