Changing product name

A desired solution could also be to show a custom attribute on the invoice instead of the product name.

This will require some custom coding, but it’s certainly possible if you know a bit of PHP.
If you only want to change this in the PDF documents produced by this plugin, you could use the wpo_wcpdf_order_item_data filter. Here’s a basic example that will do a simple search/replace:

add_filter('wpo_wcpdf_order_item_data',function( $data, $order, $document_type ){
	$replace_names = [
		'Some product' => 'alternative name',
		'Another product' => 'another alternative',
	];
	$data['name'] = str_ireplace(array_keys($replace_names),array_values($replace_names),$data['name']);

	return $data;
},10,3);

You could do much more advanced replacements based on the order data in $data if you like but that’s a bit beyond the scope of free support.

Alternatively, if you want to do this WooCommerce wide, you can use the woocommerce_order_item_name filter – this is applied in woocommerce emails, my account etc. too (as well as the invoice). Here’s a basic example (non-functional in this form):

add_filter( 'woocommerce_order_item_name', function ( $item_name, $item ) {
	// modify $item_name based on the properties/content of $item here
	return $item_name;
}, 10, 2);

Hope that helps!