Using this hook you can tell SearchWP to find partial matches even if there are exact matches in the search query

functions.php

<?php

function searchwp_partial_matches_lenient( $return, $args ) {
  // $args contains information about this request
  //   - engine
  
  // TODO: customize $return to match whether matching should be lenient
  return $return;
}

add_filter( 'searchwp_partial_matches_lenient', 'my_searchwp_partial_matches_lenient', 10, 2 );