single-post-defaults.php

<?php
if ( ! function_exists( 'inspiry_single_post_defaults' ) ) :
    /**
     * Set default values for single post settings
     *
     * @param WP_Customize_Manager $wp_customize
     */
    function inspiry_single_post_defaults( WP_Customize_Manager $wp_customize ) {
        $single_post_settings_ids = array(
            'inspiry_post_layout',
        );
        inspiry_initialize_defaults( $wp_customize, $single_post_settings_ids );
    }

    add_action( 'customize_save_after', 'inspiry_single_post_defaults' );
endif;