Conditionally add Full-Width Layout for Storefront with ACF and custom body_class

Create a True / False custom field with ACF Pro

Add this to functions.php

// =========================================================================
// FULL WIDTH CHECKBOX
// =========================================================================
function add_full_width_layout(){
     if( get_field('full_width') ){
remove_action( 'storefront_sidebar', 'storefront_get_sidebar', 10 );
       add_filter( 'body_class', function( $classes ) {
            return array_merge( $classes, array( 'page-template-template-fullwidth page-template-template-fullwidth-php ' ) );
        } );
    } 
}
add_action( 'wp', 'add_full_width_layout' );