Ability to change `with_front` about staffer

[mrwweb]

Current workaround:

<?php
add_action( 'init', 'staffer_rewrite_sans_with_front', 11 );
/**
 * change 'staff' CPT from Staffer plugin to not use `with_front` for rewrite
 */
function staffer_rewrite_sans_with_front() {
    $staff = get_post_type_object( 'staff' );
    if( $staff != false ) {
        $staff->rewrite['with_front'] = false;
        register_post_type( 'staff', (array) $staff );
    }
}