How to hide metadata from external plugin

Just read your FAQ I found the answer there.

(in case someone else encounters the same problem here is the solution.
I fixed the issue with the following code:

function bewpi_alter_hidden_order_itemmeta( $hidden_order_itemmeta ) {
    $hidden_order_itemmeta[] = '_is_giftable';
    // end so on..
    return $hidden_order_itemmeta;
}
add_filter( 'bewpi_hidden_order_itemmeta', 'bewpi_alter_hidden_order_itemmeta', 10, 1 );