Helper function to initialize default values for settings as customizer api do not do so.

initialize-defaults.php

<?php
if ( ! function_exists( 'inspiry_initialize_defaults' ) ) :
	/**
	 * Helper function to initialize default values for settings as customizer api do not do so.
	 *
	 * @param WP_Customize_Manager $wp_customize
	 * @param $inspiry_settings_ids
	 */
	function inspiry_initialize_defaults( WP_Customize_Manager $wp_customize, $inspiry_settings_ids ) {
		if ( is_array( $inspiry_settings_ids ) && ! empty( $inspiry_settings_ids ) ) {
			$mods = get_theme_mods();
			foreach ( $inspiry_settings_ids as $setting_id ) {
				$setting = $wp_customize->get_setting( $setting_id );
				if ( ! isset( $mods[ $setting->id ] ) ) {
					set_theme_mod( $setting->id, $setting->default );
				}
			}
		}
	}
endif;