Automatically filter the_excerpt() to use SearchWP Term Highlight to find a proper global excerpt

functions.php

<?php

function searchwp_term_highlight_auto_excerpt( $excerpt ) {
	global $post;

	if ( ! is_search() ) {
		return $excerpt;
	}

	// prevent recursion
	remove_filter( 'get_the_excerpt', 'searchwp_term_highlight_auto_excerpt' );

	$global_excerpt = searchwp_term_highlight_get_the_excerpt_global( $post->ID, null, get_search_query() );

	add_filter( 'get_the_excerpt', 'searchwp_term_highlight_auto_excerpt' );

	return wp_kses_post( $global_excerpt );
}

add_filter( 'get_the_excerpt', 'searchwp_term_highlight_auto_excerpt' );