Allows to define your custom elements as a layout element, so they are recognised like the section, container, block, div elements and use the same controls like query loop, flex controls, shape divider, etc.
add_filter( 'bricks/is_layout_element', function( $layout_element_names ) {
// Mark your custom element "custom_box" as a layout element
$layout_element_names[] = 'custom_box';
return $layout_element_names;
} );