Hide meta from order and emails

That’s kind of specific requirement, but right now there is no option to do it from WC Fields Factory, but you can via by handling woocommerce_order_items_meta_display hook.

Here is an idea.

function hide_wcff_meta( $output, $order ) {
	$html = '';
	$formatted_meta = $order->get_formatted( '_' );

	if ( ! empty( $formatted_meta ) ) {
		$meta_list = array();

		foreach ( $formatted_meta as $meta ) {
			/* Here you can add as many as condition you want, depends on how many fields you wanted to hide */
			if( $meta['label'] != "Your Fields Label" ) {
				$meta_list[] = '
						<dt class="variation-' . sanitize_html_class( sanitize_text_field( $meta['key'] ) ) . '">' . wp_kses_post( $meta['label'] ) . ':</dt>
						<dd class="variation-' . sanitize_html_class( sanitize_text_field( $meta['key'] ) ) . '">' . wp_kses_post( wpautop( make_clickable( $meta['value'] ) ) ) . '</dd>
					';
			}
		}

		if ( ! empty( $meta_list ) ) {
			$html .= '<dl class="variation">' . implode( '', $meta_list ) . '</dl>';
		}
	}

	return $html;
}

add_filter( 'woocommerce_order_items_meta_display', 'hide_wcff_meta', 99, 2 );